mirror of
https://github.com/youngyangyang04/leetcode-master.git
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Merge branch 'master' into 添加0070组合优化Go版本
This commit is contained in:
QuinnDK
16
README.md
16
README.md
@ -3,7 +3,8 @@
|
||||
> 1. **介绍**：本项目是一套完整的刷题计划，旨在帮助大家少走弯路，循序渐进学算法，[关注作者](#关于作者)
|
||||
> 2. **PDF版本** ： [「代码随想录」算法精讲 PDF 版本](https://mp.weixin.qq.com/s/RsdcQ9umo09R6cfnwXZlrQ) 。
|
||||
> 3. **学习社区** : 一起学习打卡/面试技巧/如何选择offer/大厂内推/职场规则/简历修改/技术分享/程序人生。欢迎加入[「代码随想录」学习社区](https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ) 。
|
||||
> 4. **转载须知** ：以下所有文章皆为我（[程序员Carl](https://github.com/youngyangyang04)）的原创。引用本项目文章请注明出处，发现恶意抄袭或搬运，会动用法律武器维护自己的权益。让我们一起维护一个良好的技术创作环境！
|
||||
> 4. **提交代码**：本项目统一使用C++语言进行讲解，但已经有Java、Python、Go、JavaScript等等多语言版本，感谢[这里的每一位贡献者](https://github.com/youngyangyang04/leetcode-master/graphs/contributors)，如果你也想贡献代码点亮你的头像，[点击这里](https://mp.weixin.qq.com/s/tqCxrMEU-ajQumL1i8im9A)了解提交代码的方式。
|
||||
> 5. **转载须知** ：以下所有文章皆为我（[程序员Carl](https://github.com/youngyangyang04)）的原创。引用本项目文章请注明出处，发现恶意抄袭或搬运，会动用法律武器维护自己的权益。让我们一起维护一个良好的技术创作环境！
|
||||
|
||||
<p align="center">
|
||||
<a href="https://github.com/youngyangyang04/leetcode-master" target="_blank">
|
||||
@ -169,10 +170,9 @@
|
||||
6. [链表：删除链表的倒数第 N 个结点](./problems/0019.删除链表的倒数第N个节点.md)
|
||||
7. [链表：链表相交](./problems/面试题02.07.链表相交.md)
|
||||
8. [链表：环找到了，那入口呢？](./problems/0142.环形链表II.md)
|
||||
9. [链表：删除链表的倒数第 N 个结点](./problems/0019.删除链表的倒数第N个节点.md)
|
||||
10. [哈希表：解决了两数之和，那么能解决三数之和么？](./problems/0015.三数之和.md)
|
||||
11. [双指针法：一样的道理，能解决四数之和](./problems/0018.四数之和.md)
|
||||
12. [双指针法：总结篇！](./problems/双指针总结.md)
|
||||
9. [哈希表：解决了两数之和，那么能解决三数之和么？](./problems/0015.三数之和.md)
|
||||
10. [双指针法：一样的道理，能解决四数之和](./problems/0018.四数之和.md)
|
||||
11. [双指针法：总结篇！](./problems/双指针总结.md)
|
||||
|
||||
## 栈与队列
|
||||
|
||||
@ -409,6 +409,10 @@
|
||||
|
||||
（持续更新中....）
|
||||
|
||||
# 贡献者
|
||||
|
||||
你可以[点此链接](https://github.com/youngyangyang04/leetcode-master/graphs/contributors)查看LeetCode-Master的所有贡献者。感谢你们补充了LeetCode-Master的其他语言版本，让更多的读者收益于此项目。
|
||||
|
||||
# 关于作者
|
||||
|
||||
大家好，我是程序员Carl，哈工大师兄，ACM 校赛、黑龙江省赛、东北四省赛金牌、亚洲区域赛铜牌获得者，先后在腾讯和百度从事后端技术研发，CSDN博客专家。对算法和C++后端技术有一定的见解，利用工作之余重新刷leetcode。
|
||||
@ -420,7 +424,7 @@
|
||||
<a name="微信"></a>
|
||||
<img src="https://img-blog.csdnimg.cn/20200814140330894.png" data-img="1" width="175" height="175">
|
||||
|
||||
# 我的公众号
|
||||
# 公众号
|
||||
|
||||
更多精彩文章持续更新，微信搜索：「代码随想录」第一时间围观，关注后回复：「666」可以获得所有算法专题原创PDF。
|
||||
|
||||
|
||||
@ -1,10 +1,10 @@
|
||||
<p align="center">
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/RsdcQ9umo09R6cfnwXZlrQ"><img src="https://img.shields.io/badge/PDF下载-代码随想录-blueviolet" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw"><img src="https://img.shields.io/badge/刷题-微信群-green" alt=""></a>
|
||||
<a href="https://img-blog.csdnimg.cn/20201210231711160.png"><img src="https://img.shields.io/badge/公众号-代码随想录-brightgreen" alt=""></a>
|
||||
<a href="https://space.bilibili.com/525438321"><img src="https://img.shields.io/badge/B站-代码随想录-orange" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
</p>
|
||||
<p align="center"><strong>欢迎大家参与本项目，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
<p align="center"><strong>欢迎大家<a href="https://mp.weixin.qq.com/s/tqCxrMEU-ajQumL1i8im9A">参与本项目</a>，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
|
||||
|
||||
## 1. 两数之和
|
||||
@ -37,9 +37,9 @@ https://leetcode-cn.com/problems/two-sum/
|
||||
本题呢，则要使用map，那么来看一下使用数组和set来做哈希法的局限。
|
||||
|
||||
* 数组的大小是受限制的，而且如果元素很少，而哈希值太大会造成内存空间的浪费。
|
||||
* set是一个集合，里面放的元素只能是一个key，而两数之和这道题目，不仅要判断y是否存在而且还要记录y的下表位置，因为要返回x 和 y的下表。所以set 也不能用。
|
||||
* set是一个集合，里面放的元素只能是一个key，而两数之和这道题目，不仅要判断y是否存在而且还要记录y的下标位置，因为要返回x 和 y的下标。所以set 也不能用。
|
||||
|
||||
此时就要选择另一种数据结构：map ，map是一种key value的存储结构，可以用key保存数值，用value在保存数值所在的下表。
|
||||
此时就要选择另一种数据结构：map ，map是一种key value的存储结构，可以用key保存数值，用value在保存数值所在的下标。
|
||||
|
||||
C++中map，有三种类型：
|
||||
|
||||
@ -156,6 +156,21 @@ impl Solution {
|
||||
}
|
||||
```
|
||||
|
||||
Javascript
|
||||
|
||||
```javascript
|
||||
var twoSum = function (nums, target) {
|
||||
let hash = {};
|
||||
for (let i = 0; i < nums.length; i++) {
|
||||
if (hash[target - nums[i]] !== undefined) {
|
||||
return [i, hash[target - nums[i]]];
|
||||
}
|
||||
hash[nums[i]] = i;
|
||||
}
|
||||
return [];
|
||||
};
|
||||
```
|
||||
|
||||
|
||||
|
||||
|
||||
@ -163,4 +178,4 @@ impl Solution {
|
||||
* 作者微信：[程序员Carl](https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw)
|
||||
* B站视频：[代码随想录](https://space.bilibili.com/525438321)
|
||||
* 知识星球：[代码随想录](https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ)
|
||||
<div align="center"><img src=../pics/公众号.png width=450 alt=> </img></div>
|
||||
<div align="center"><img src=../pics/公众号.png width=450 alt=> </img></div>
|
||||
|
||||
@ -1,10 +1,10 @@
|
||||
<p align="center">
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/RsdcQ9umo09R6cfnwXZlrQ"><img src="https://img.shields.io/badge/PDF下载-代码随想录-blueviolet" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw"><img src="https://img.shields.io/badge/刷题-微信群-green" alt=""></a>
|
||||
<a href="https://img-blog.csdnimg.cn/20201210231711160.png"><img src="https://img.shields.io/badge/公众号-代码随想录-brightgreen" alt=""></a>
|
||||
<a href="https://space.bilibili.com/525438321"><img src="https://img.shields.io/badge/B站-代码随想录-orange" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
</p>
|
||||
<p align="center"><strong>欢迎大家参与本项目，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
<p align="center"><strong>欢迎大家<a href="https://mp.weixin.qq.com/s/tqCxrMEU-ajQumL1i8im9A">参与本项目</a>，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
|
||||
|
||||
|
||||
@ -218,8 +218,33 @@ class Solution {
|
||||
```
|
||||
|
||||
Python：
|
||||
|
||||
|
||||
```Python
|
||||
class Solution:
|
||||
def threeSum(self, nums):
|
||||
ans = []
|
||||
n = len(nums)
|
||||
nums.sort()
|
||||
for i in range(n):
|
||||
left = i + 1
|
||||
right = n - 1
|
||||
if nums[i] > 0:
|
||||
break
|
||||
if i >= 1 and nums[i] == nums[i - 1]:
|
||||
continue
|
||||
while left < right:
|
||||
total = nums[i] + nums[left] + nums[right]
|
||||
if total > 0:
|
||||
right -= 1
|
||||
elif total < 0:
|
||||
left += 1
|
||||
else:
|
||||
ans.append([nums[i], nums[left], nums[right]])
|
||||
while left != right and nums[left] == nums[left + 1]: left += 1
|
||||
while left != right and nums[right] == nums[right - 1]: right -= 1
|
||||
left += 1
|
||||
right -= 1
|
||||
return ans
|
||||
```
|
||||
Go：
|
||||
```Go
|
||||
func threeSum(nums []int)[][]int{
|
||||
@ -256,6 +281,59 @@ func threeSum(nums []int)[][]int{
|
||||
}
|
||||
```
|
||||
|
||||
javaScript:
|
||||
|
||||
```js
|
||||
/**
|
||||
* @param {number[]} nums
|
||||
* @return {number[][]}
|
||||
*/
|
||||
|
||||
// 循环内不考虑去重
|
||||
var threeSum = function(nums) {
|
||||
const len = nums.length;
|
||||
if(len < 3) return [];
|
||||
nums.sort((a, b) => a - b);
|
||||
const resSet = new Set();
|
||||
for(let i = 0; i < len - 2; i++) {
|
||||
if(nums[i] > 0) break;
|
||||
let l = i + 1, r = len - 1;
|
||||
while(l < r) {
|
||||
const sum = nums[i] + nums[l] + nums[r];
|
||||
if(sum < 0) { l++; continue };
|
||||
if(sum > 0) { r--; continue };
|
||||
resSet.add(`${nums[i]},${nums[l]},${nums[r]}`);
|
||||
l++;
|
||||
r--;
|
||||
}
|
||||
}
|
||||
return Array.from(resSet).map(i => i.split(","));
|
||||
};
|
||||
|
||||
// 去重优化
|
||||
var threeSum = function(nums) {
|
||||
const len = nums.length;
|
||||
if(len < 3) return [];
|
||||
nums.sort((a, b) => a - b);
|
||||
const res = [];
|
||||
for(let i = 0; i < len - 2; i++) {
|
||||
if(nums[i] > 0) break;
|
||||
// a去重
|
||||
if(i > 0 && nums[i] === nums[i - 1]) continue;
|
||||
let l = i + 1, r = len - 1;
|
||||
while(l < r) {
|
||||
const sum = nums[i] + nums[l] + nums[r];
|
||||
if(sum < 0) { l++; continue };
|
||||
if(sum > 0) { r--; continue };
|
||||
res.push([nums[i], nums[l], nums[r]])
|
||||
// b c 去重
|
||||
while(l < r && nums[l] === nums[++l]);
|
||||
while(l < r && nums[r] === nums[--r]);
|
||||
}
|
||||
}
|
||||
return res;
|
||||
};
|
||||
```
|
||||
|
||||
|
||||
|
||||
|
||||
@ -1,10 +1,10 @@
|
||||
<p align="center">
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/RsdcQ9umo09R6cfnwXZlrQ"><img src="https://img.shields.io/badge/PDF下载-代码随想录-blueviolet" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw"><img src="https://img.shields.io/badge/刷题-微信群-green" alt=""></a>
|
||||
<a href="https://img-blog.csdnimg.cn/20201210231711160.png"><img src="https://img.shields.io/badge/公众号-代码随想录-brightgreen" alt=""></a>
|
||||
<a href="https://space.bilibili.com/525438321"><img src="https://img.shields.io/badge/B站-代码随想录-orange" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
</p>
|
||||
<p align="center"><strong>欢迎大家参与本项目，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
<p align="center"><strong>欢迎大家<a href="https://mp.weixin.qq.com/s/tqCxrMEU-ajQumL1i8im9A">参与本项目</a>，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
|
||||
|
||||
# 17.电话号码的字母组合
|
||||
|
||||
@ -1,10 +1,10 @@
|
||||
<p align="center">
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/RsdcQ9umo09R6cfnwXZlrQ"><img src="https://img.shields.io/badge/PDF下载-代码随想录-blueviolet" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw"><img src="https://img.shields.io/badge/刷题-微信群-green" alt=""></a>
|
||||
<a href="https://img-blog.csdnimg.cn/20201210231711160.png"><img src="https://img.shields.io/badge/公众号-代码随想录-brightgreen" alt=""></a>
|
||||
<a href="https://space.bilibili.com/525438321"><img src="https://img.shields.io/badge/B站-代码随想录-orange" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
</p>
|
||||
<p align="center"><strong>欢迎大家参与本项目，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
<p align="center"><strong>欢迎大家<a href="https://mp.weixin.qq.com/s/tqCxrMEU-ajQumL1i8im9A">参与本项目</a>，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
|
||||
|
||||
> 一样的道理，能解决四数之和
|
||||
@ -165,11 +165,75 @@ class Solution {
|
||||
```
|
||||
|
||||
Python：
|
||||
```python
|
||||
|
||||
class Solution(object):
|
||||
def fourSum(self, nums, target):
|
||||
"""
|
||||
:type nums: List[int]
|
||||
:type target: int
|
||||
:rtype: List[List[int]]
|
||||
"""
|
||||
# use a dict to store value:showtimes
|
||||
hashmap = dict()
|
||||
for n in nums:
|
||||
if n in hashmap:
|
||||
hashmap[n] += 1
|
||||
else:
|
||||
hashmap[n] = 1
|
||||
|
||||
# good thing about using python is you can use set to drop duplicates.
|
||||
ans = set()
|
||||
for i in range(len(nums)):
|
||||
for j in range(i + 1, len(nums)):
|
||||
for k in range(j + 1, len(nums)):
|
||||
val = target - (nums[i] + nums[j] + nums[k])
|
||||
if val in hashmap:
|
||||
# make sure no duplicates.
|
||||
count = (nums[i] == val) + (nums[j] == val) + (nums[k] == val)
|
||||
if hashmap[val] > count:
|
||||
ans.add(tuple(sorted([nums[i], nums[j], nums[k], val])))
|
||||
else:
|
||||
continue
|
||||
return ans
|
||||
|
||||
```
|
||||
|
||||
Go：
|
||||
|
||||
javaScript:
|
||||
|
||||
```js
|
||||
/**
|
||||
* @param {number[]} nums
|
||||
* @param {number} target
|
||||
* @return {number[][]}
|
||||
*/
|
||||
var fourSum = function(nums, target) {
|
||||
const len = nums.length;
|
||||
if(len < 4) return [];
|
||||
nums.sort((a, b) => a - b);
|
||||
const res = [];
|
||||
for(let i = 0; i < len - 3; i++) {
|
||||
// 去重i
|
||||
if(i > 0 && nums[i] === nums[i - 1]) continue;
|
||||
for(let j = i + 1; j < len - 2; j++) {
|
||||
// 去重j
|
||||
if(j > i + 1 && nums[j] === nums[j - 1]) continue;
|
||||
let l = j + 1, r = len - 1;
|
||||
while(l < r) {
|
||||
const sum = nums[i] + nums[j] + nums[l] + nums[r];
|
||||
if(sum < target) { l++; continue}
|
||||
if(sum > target) { r--; continue}
|
||||
res.push([nums[i], nums[j], nums[l], nums[r]]);
|
||||
while(l < r && nums[l] === nums[++l]);
|
||||
while(l < r && nums[r] === nums[--r]);
|
||||
}
|
||||
}
|
||||
}
|
||||
return res;
|
||||
};
|
||||
```
|
||||
|
||||
|
||||
-----------------------
|
||||
|
||||
@ -1,10 +1,10 @@
|
||||
<p align="center">
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/RsdcQ9umo09R6cfnwXZlrQ"><img src="https://img.shields.io/badge/PDF下载-代码随想录-blueviolet" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw"><img src="https://img.shields.io/badge/刷题-微信群-green" alt=""></a>
|
||||
<a href="https://img-blog.csdnimg.cn/20201210231711160.png"><img src="https://img.shields.io/badge/公众号-代码随想录-brightgreen" alt=""></a>
|
||||
<a href="https://space.bilibili.com/525438321"><img src="https://img.shields.io/badge/B站-代码随想录-orange" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
</p>
|
||||
<p align="center"><strong>欢迎大家参与本项目，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
<p align="center"><strong>欢迎大家<a href="https://mp.weixin.qq.com/s/tqCxrMEU-ajQumL1i8im9A">参与本项目</a>，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
|
||||
|
||||
|
||||
@ -135,6 +135,28 @@ func removeNthFromEnd(head *ListNode, n int) *ListNode {
|
||||
}
|
||||
```
|
||||
|
||||
JavaScript:
|
||||
|
||||
```js
|
||||
/**
|
||||
* @param {ListNode} head
|
||||
* @param {number} n
|
||||
* @return {ListNode}
|
||||
*/
|
||||
var removeNthFromEnd = function(head, n) {
|
||||
let ret = new ListNode(0, head),
|
||||
slow = fast = ret;
|
||||
while(n--) fast = fast.next;
|
||||
if(!fast) return ret.next;
|
||||
while (fast.next) {
|
||||
fast = fast.next;
|
||||
slow = slow.next
|
||||
};
|
||||
slow.next = slow.next.next;
|
||||
return ret.next;
|
||||
};
|
||||
```
|
||||
|
||||
-----------------------
|
||||
* 作者微信：[程序员Carl](https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw)
|
||||
* B站视频：[代码随想录](https://space.bilibili.com/525438321)
|
||||
|
||||
@ -1,10 +1,10 @@
|
||||
<p align="center">
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/RsdcQ9umo09R6cfnwXZlrQ"><img src="https://img.shields.io/badge/PDF下载-代码随想录-blueviolet" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw"><img src="https://img.shields.io/badge/刷题-微信群-green" alt=""></a>
|
||||
<a href="https://img-blog.csdnimg.cn/20201210231711160.png"><img src="https://img.shields.io/badge/公众号-代码随想录-brightgreen" alt=""></a>
|
||||
<a href="https://space.bilibili.com/525438321"><img src="https://img.shields.io/badge/B站-代码随想录-orange" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
</p>
|
||||
<p align="center"><strong>欢迎大家参与本项目，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
<p align="center"><strong>欢迎大家<a href="https://mp.weixin.qq.com/s/tqCxrMEU-ajQumL1i8im9A">参与本项目</a>，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
|
||||
|
||||
|
||||
@ -247,6 +247,32 @@ def is_valid(strs)
|
||||
end
|
||||
```
|
||||
|
||||
Javascript:
|
||||
```javascript
|
||||
var isValid = function (s) {
|
||||
const stack = [];
|
||||
for (let i = 0; i < s.length; i++) {
|
||||
let c = s[i];
|
||||
switch (c) {
|
||||
case '(':
|
||||
stack.push(')');
|
||||
break;
|
||||
case '[':
|
||||
stack.push(']');
|
||||
break;
|
||||
case '{':
|
||||
stack.push('}');
|
||||
break;
|
||||
default:
|
||||
if (c !== stack.pop()) {
|
||||
return false;
|
||||
}
|
||||
}
|
||||
}
|
||||
return stack.length === 0;
|
||||
};
|
||||
```
|
||||
|
||||
|
||||
-----------------------
|
||||
* 作者微信：[程序员Carl](https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw)
|
||||
|
||||
@ -1,11 +1,11 @@
|
||||
|
||||
<p align="center">
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/RsdcQ9umo09R6cfnwXZlrQ"><img src="https://img.shields.io/badge/PDF下载-代码随想录-blueviolet" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw"><img src="https://img.shields.io/badge/刷题-微信群-green" alt=""></a>
|
||||
<a href="https://img-blog.csdnimg.cn/20201210231711160.png"><img src="https://img.shields.io/badge/公众号-代码随想录-brightgreen" alt=""></a>
|
||||
<a href="https://space.bilibili.com/525438321"><img src="https://img.shields.io/badge/B站-代码随想录-orange" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
</p>
|
||||
<p align="center"><strong>欢迎大家参与本项目，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
<p align="center"><strong>欢迎大家<a href="https://mp.weixin.qq.com/s/tqCxrMEU-ajQumL1i8im9A">参与本项目</a>，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
|
||||
|
||||
## 24. 两两交换链表中的节点
|
||||
|
||||
@ -132,6 +132,21 @@ Python：
|
||||
|
||||
Go：
|
||||
|
||||
Javascript:
|
||||
```javascript
|
||||
var swapPairs = function (head) {
|
||||
let ret = new ListNode(0, head), temp = ret;
|
||||
while (temp.next && temp.next.next) {
|
||||
let cur = temp.next.next, pre = temp.next;
|
||||
pre.next = cur.next;
|
||||
cur.next = pre;
|
||||
temp.next = cur;
|
||||
temp = pre;
|
||||
}
|
||||
return ret.next;
|
||||
};
|
||||
```
|
||||
|
||||
|
||||
-----------------------
|
||||
* 作者微信：[程序员Carl](https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw)
|
||||
|
||||
@ -1,10 +1,10 @@
|
||||
<p align="center">
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/RsdcQ9umo09R6cfnwXZlrQ"><img src="https://img.shields.io/badge/PDF下载-代码随想录-blueviolet" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw"><img src="https://img.shields.io/badge/刷题-微信群-green" alt=""></a>
|
||||
<a href="https://img-blog.csdnimg.cn/20201210231711160.png"><img src="https://img.shields.io/badge/公众号-代码随想录-brightgreen" alt=""></a>
|
||||
<a href="https://space.bilibili.com/525438321"><img src="https://img.shields.io/badge/B站-代码随想录-orange" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
</p>
|
||||
<p align="center"><strong>欢迎大家参与本项目，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
<p align="center"><strong>欢迎大家<a href="https://mp.weixin.qq.com/s/tqCxrMEU-ajQumL1i8im9A">参与本项目</a>，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
|
||||
|
||||
## 27. 移除元素
|
||||
|
||||
@ -1,10 +1,10 @@
|
||||
<p align="center">
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/RsdcQ9umo09R6cfnwXZlrQ"><img src="https://img.shields.io/badge/PDF下载-代码随想录-blueviolet" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw"><img src="https://img.shields.io/badge/刷题-微信群-green" alt=""></a>
|
||||
<a href="https://img-blog.csdnimg.cn/20201210231711160.png"><img src="https://img.shields.io/badge/公众号-代码随想录-brightgreen" alt=""></a>
|
||||
<a href="https://space.bilibili.com/525438321"><img src="https://img.shields.io/badge/B站-代码随想录-orange" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
</p>
|
||||
<p align="center"><strong>欢迎大家参与本项目，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
<p align="center"><strong>欢迎大家<a href="https://mp.weixin.qq.com/s/tqCxrMEU-ajQumL1i8im9A">参与本项目</a>，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
|
||||
|
||||
> 在一个串中查找是否出现过另一个串，这是KMP的看家本领。
|
||||
|
||||
@ -1,10 +1,10 @@
|
||||
<p align="center">
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/RsdcQ9umo09R6cfnwXZlrQ"><img src="https://img.shields.io/badge/PDF下载-代码随想录-blueviolet" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw"><img src="https://img.shields.io/badge/刷题-微信群-green" alt=""></a>
|
||||
<a href="https://img-blog.csdnimg.cn/20201210231711160.png"><img src="https://img.shields.io/badge/公众号-代码随想录-brightgreen" alt=""></a>
|
||||
<a href="https://space.bilibili.com/525438321"><img src="https://img.shields.io/badge/B站-代码随想录-orange" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
</p>
|
||||
<p align="center"><strong>欢迎大家参与本项目，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
<p align="center"><strong>欢迎大家<a href="https://mp.weixin.qq.com/s/tqCxrMEU-ajQumL1i8im9A">参与本项目</a>，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
|
||||
|
||||
|
||||
@ -116,7 +116,7 @@ public:
|
||||
|
||||
**大家要仔细看注释，思考为什么要写while(left <= right)， 为什么要写right = middle - 1**。
|
||||
|
||||
```
|
||||
```C++
|
||||
class Solution {
|
||||
public:
|
||||
int searchInsert(vector<int>& nums, int target) {
|
||||
@ -158,7 +158,7 @@ public:
|
||||
|
||||
**大家要仔细看注释，思考为什么要写while (left < right)， 为什么要写right = middle**。
|
||||
|
||||
```
|
||||
```C++
|
||||
class Solution {
|
||||
public:
|
||||
int searchInsert(vector<int>& nums, int target) {
|
||||
|
||||
@ -1,10 +1,10 @@
|
||||
<p align="center">
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/RsdcQ9umo09R6cfnwXZlrQ"><img src="https://img.shields.io/badge/PDF下载-代码随想录-blueviolet" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw"><img src="https://img.shields.io/badge/刷题-微信群-green" alt=""></a>
|
||||
<a href="https://img-blog.csdnimg.cn/20201210231711160.png"><img src="https://img.shields.io/badge/公众号-代码随想录-brightgreen" alt=""></a>
|
||||
<a href="https://space.bilibili.com/525438321"><img src="https://img.shields.io/badge/B站-代码随想录-orange" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
</p>
|
||||
<p align="center"><strong>欢迎大家参与本项目，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
<p align="center"><strong>欢迎大家<a href="https://mp.weixin.qq.com/s/tqCxrMEU-ajQumL1i8im9A">参与本项目</a>，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
|
||||
|
||||
如果对回溯法理论还不清楚的同学，可以先看这个视频[视频来了！！带你学透回溯算法（理论篇）](https://mp.weixin.qq.com/s/wDd5azGIYWjbU0fdua_qBg)
|
||||
|
||||
@ -1,10 +1,10 @@
|
||||
<p align="center">
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/RsdcQ9umo09R6cfnwXZlrQ"><img src="https://img.shields.io/badge/PDF下载-代码随想录-blueviolet" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw"><img src="https://img.shields.io/badge/刷题-微信群-green" alt=""></a>
|
||||
<a href="https://img-blog.csdnimg.cn/20201210231711160.png"><img src="https://img.shields.io/badge/公众号-代码随想录-brightgreen" alt=""></a>
|
||||
<a href="https://space.bilibili.com/525438321"><img src="https://img.shields.io/badge/B站-代码随想录-orange" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
</p>
|
||||
<p align="center"><strong>欢迎大家参与本项目，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
<p align="center"><strong>欢迎大家<a href="https://mp.weixin.qq.com/s/tqCxrMEU-ajQumL1i8im9A">参与本项目</a>，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
|
||||
|
||||
## 39. 组合总和
|
||||
|
||||
@ -1,10 +1,10 @@
|
||||
<p align="center">
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/RsdcQ9umo09R6cfnwXZlrQ"><img src="https://img.shields.io/badge/PDF下载-代码随想录-blueviolet" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw"><img src="https://img.shields.io/badge/刷题-微信群-green" alt=""></a>
|
||||
<a href="https://img-blog.csdnimg.cn/20201210231711160.png"><img src="https://img.shields.io/badge/公众号-代码随想录-brightgreen" alt=""></a>
|
||||
<a href="https://space.bilibili.com/525438321"><img src="https://img.shields.io/badge/B站-代码随想录-orange" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
</p>
|
||||
<p align="center"><strong>欢迎大家参与本项目，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
<p align="center"><strong>欢迎大家<a href="https://mp.weixin.qq.com/s/tqCxrMEU-ajQumL1i8im9A">参与本项目</a>，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
|
||||
|
||||
> 这篇可以说是全网把组合问题如何去重，讲的最清晰的了！
|
||||
|
||||
@ -1,10 +1,10 @@
|
||||
<p align="center">
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/RsdcQ9umo09R6cfnwXZlrQ"><img src="https://img.shields.io/badge/PDF下载-代码随想录-blueviolet" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw"><img src="https://img.shields.io/badge/刷题-微信群-green" alt=""></a>
|
||||
<a href="https://img-blog.csdnimg.cn/20201210231711160.png"><img src="https://img.shields.io/badge/公众号-代码随想录-brightgreen" alt=""></a>
|
||||
<a href="https://space.bilibili.com/525438321"><img src="https://img.shields.io/badge/B站-代码随想录-orange" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
</p>
|
||||
<p align="center"><strong>欢迎大家参与本项目，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
<p align="center"><strong>欢迎大家<a href="https://mp.weixin.qq.com/s/tqCxrMEU-ajQumL1i8im9A">参与本项目</a>，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
|
||||
|
||||
> 相对于[贪心算法：跳跃游戏](https://mp.weixin.qq.com/s/606_N9j8ACKCODoCbV1lSA)难了不少，做好心里准备！
|
||||
@ -193,6 +193,26 @@ class Solution:
|
||||
```
|
||||
|
||||
Go：
|
||||
```Go
|
||||
func jump(nums []int) int {
|
||||
dp:=make([]int ,len(nums))
|
||||
dp[0]=0
|
||||
|
||||
for i:=1;i<len(nums);i++{
|
||||
dp[i]=i
|
||||
for j:=0;j<i;j++{
|
||||
if nums[j]+j>i{
|
||||
dp[i]=min(dp[j]+1,dp[i])
|
||||
}
|
||||
}
|
||||
}
|
||||
return dp[len(nums)-1]
|
||||
}
|
||||
/*
|
||||
dp[i]表示从起点到当前位置的最小跳跃次数
|
||||
dp[i]=min(dp[j]+1,dp[i]) 表示从j位置用一步跳跃到当前位置，这个j位置可能有很多个，却最小一个就可以
|
||||
*/
|
||||
```
|
||||
|
||||
|
||||
|
||||
|
||||
@ -1,10 +1,10 @@
|
||||
<p align="center">
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/RsdcQ9umo09R6cfnwXZlrQ"><img src="https://img.shields.io/badge/PDF下载-代码随想录-blueviolet" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw"><img src="https://img.shields.io/badge/刷题-微信群-green" alt=""></a>
|
||||
<a href="https://img-blog.csdnimg.cn/20201210231711160.png"><img src="https://img.shields.io/badge/公众号-代码随想录-brightgreen" alt=""></a>
|
||||
<a href="https://space.bilibili.com/525438321"><img src="https://img.shields.io/badge/B站-代码随想录-orange" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
</p>
|
||||
<p align="center"><strong>欢迎大家参与本项目，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
<p align="center"><strong>欢迎大家<a href="https://mp.weixin.qq.com/s/tqCxrMEU-ajQumL1i8im9A">参与本项目</a>，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
|
||||
|
||||
## 46.全排列
|
||||
@ -206,14 +206,33 @@ func backtrack(nums,pathNums []int,used []bool){
|
||||
}
|
||||
}
|
||||
|
||||
func permute(nums []int) [][]int {
|
||||
//var pathNums []int
|
||||
pathNums:=make([]int,0)
|
||||
var used=make([]bool,len(nums))
|
||||
result=[][]int{}
|
||||
backtrack(nums,pathNums,used)
|
||||
Javascript:
|
||||
|
||||
```javascript
|
||||
|
||||
var permute = function(nums) {
|
||||
let result = []
|
||||
let path = []
|
||||
function backtracing(used) {
|
||||
if(path.length === nums.length) {
|
||||
result.push(path.slice(0))
|
||||
return
|
||||
}
|
||||
for(let i = 0; i < nums.length; i++) {
|
||||
if(used[nums[i]]) {
|
||||
continue
|
||||
}
|
||||
used[nums[i]] = true
|
||||
path.push(nums[i])
|
||||
backtracing(used)
|
||||
path.pop()
|
||||
used[nums[i]] = false
|
||||
}
|
||||
}
|
||||
backtracing([])
|
||||
return result
|
||||
}
|
||||
};
|
||||
|
||||
```
|
||||
|
||||
|
||||
|
||||
@ -1,10 +1,10 @@
|
||||
<p align="center">
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/RsdcQ9umo09R6cfnwXZlrQ"><img src="https://img.shields.io/badge/PDF下载-代码随想录-blueviolet" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw"><img src="https://img.shields.io/badge/刷题-微信群-green" alt=""></a>
|
||||
<a href="https://img-blog.csdnimg.cn/20201210231711160.png"><img src="https://img.shields.io/badge/公众号-代码随想录-brightgreen" alt=""></a>
|
||||
<a href="https://space.bilibili.com/525438321"><img src="https://img.shields.io/badge/B站-代码随想录-orange" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
</p>
|
||||
<p align="center"><strong>欢迎大家参与本项目，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
<p align="center"><strong>欢迎大家<a href="https://mp.weixin.qq.com/s/tqCxrMEU-ajQumL1i8im9A">参与本项目</a>，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
# 排列问题（二）
|
||||
|
||||
## 47.全排列 II
|
||||
@ -85,7 +85,7 @@ public:
|
||||
path.clear();
|
||||
sort(nums.begin(), nums.end()); // 排序
|
||||
vector<bool> used(nums.size(), false);
|
||||
backtracking(nums, vec, used);
|
||||
backtracking(nums, used);
|
||||
return result;
|
||||
}
|
||||
};
|
||||
@ -220,6 +220,43 @@ class Solution:
|
||||
return res
|
||||
```
|
||||
|
||||
Javascript:
|
||||
|
||||
```javascript
|
||||
|
||||
var permuteUnique = function (nums) {
|
||||
nums.sort((a, b) => {
|
||||
return a - b
|
||||
})
|
||||
let result = []
|
||||
let path = []
|
||||
|
||||
function backtracing( used) {
|
||||
if (path.length === nums.length) {
|
||||
result.push(path.slice())
|
||||
return
|
||||
}
|
||||
for (let i = 0; i < nums.length; i++) {
|
||||
if (i > 0 && nums[i] === nums[i - 1] && !used[i - 1]) {
|
||||
continue
|
||||
}
|
||||
if (!used[i]) {
|
||||
used[i] = true
|
||||
path.push(nums[i])
|
||||
backtracing(used)
|
||||
path.pop()
|
||||
used[i] = false
|
||||
}
|
||||
|
||||
|
||||
}
|
||||
}
|
||||
backtracing([])
|
||||
return result
|
||||
};
|
||||
|
||||
```
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
@ -1,10 +1,10 @@
|
||||
<p align="center">
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/RsdcQ9umo09R6cfnwXZlrQ"><img src="https://img.shields.io/badge/PDF下载-代码随想录-blueviolet" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw"><img src="https://img.shields.io/badge/刷题-微信群-green" alt=""></a>
|
||||
<a href="https://img-blog.csdnimg.cn/20201210231711160.png"><img src="https://img.shields.io/badge/公众号-代码随想录-brightgreen" alt=""></a>
|
||||
<a href="https://space.bilibili.com/525438321"><img src="https://img.shields.io/badge/B站-代码随想录-orange" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
</p>
|
||||
<p align="center"><strong>欢迎大家参与本项目，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
<p align="center"><strong>欢迎大家<a href="https://mp.weixin.qq.com/s/tqCxrMEU-ajQumL1i8im9A">参与本项目</a>，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
|
||||
|
||||
## 第51题. N皇后
|
||||
|
||||
@ -1,10 +1,10 @@
|
||||
<p align="center">
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/RsdcQ9umo09R6cfnwXZlrQ"><img src="https://img.shields.io/badge/PDF下载-代码随想录-blueviolet" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw"><img src="https://img.shields.io/badge/刷题-微信群-green" alt=""></a>
|
||||
<a href="https://img-blog.csdnimg.cn/20201210231711160.png"><img src="https://img.shields.io/badge/公众号-代码随想录-brightgreen" alt=""></a>
|
||||
<a href="https://space.bilibili.com/525438321"><img src="https://img.shields.io/badge/B站-代码随想录-orange" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
</p>
|
||||
<p align="center"><strong>欢迎大家参与本项目，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
<p align="center"><strong>欢迎大家<a href="https://mp.weixin.qq.com/s/tqCxrMEU-ajQumL1i8im9A">参与本项目</a>，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
|
||||
|
||||
## 53. 最大子序和
|
||||
@ -175,31 +175,25 @@ class Solution:
|
||||
```
|
||||
|
||||
Go：
|
||||
```Go
|
||||
func maxSubArray(nums []int) int {
|
||||
if len(nums)<1{
|
||||
return 0
|
||||
}
|
||||
dp:=make([]int,len(nums))
|
||||
result:=nums[0]
|
||||
dp[0]=nums[0]
|
||||
for i:=1;i<len(nums);i++{
|
||||
dp[i]=max(dp[i-1]+nums[i],nums[i])
|
||||
result=max(dp[i],result)
|
||||
}
|
||||
return result
|
||||
}
|
||||
|
||||
func max(a,b int)int{
|
||||
if a>b{
|
||||
return a
|
||||
}else{
|
||||
return b
|
||||
```go
|
||||
func maxSubArray(nums []int) int {
|
||||
maxSum := nums[0]
|
||||
for i := 1; i < len(nums); i++ {
|
||||
if nums[i] + nums[i-1] > nums[i] {
|
||||
nums[i] += nums[i-1]
|
||||
}
|
||||
if nums[i] > maxSum {
|
||||
maxSum = nums[i]
|
||||
}
|
||||
}
|
||||
return maxSum
|
||||
}
|
||||
```
|
||||
|
||||
|
||||
|
||||
|
||||
-----------------------
|
||||
* 作者微信：[程序员Carl](https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw)
|
||||
* B站视频：[代码随想录](https://space.bilibili.com/525438321)
|
||||
|
||||
@ -1,10 +1,10 @@
|
||||
<p align="center">
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/RsdcQ9umo09R6cfnwXZlrQ"><img src="https://img.shields.io/badge/PDF下载-代码随想录-blueviolet" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw"><img src="https://img.shields.io/badge/刷题-微信群-green" alt=""></a>
|
||||
<a href="https://img-blog.csdnimg.cn/20201210231711160.png"><img src="https://img.shields.io/badge/公众号-代码随想录-brightgreen" alt=""></a>
|
||||
<a href="https://space.bilibili.com/525438321"><img src="https://img.shields.io/badge/B站-代码随想录-orange" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
</p>
|
||||
<p align="center"><strong>欢迎大家参与本项目，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
<p align="center"><strong>欢迎大家<a href="https://mp.weixin.qq.com/s/tqCxrMEU-ajQumL1i8im9A">参与本项目</a>，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
|
||||
## 53. 最大子序和
|
||||
|
||||
|
||||
@ -1,10 +1,10 @@
|
||||
<p align="center">
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/RsdcQ9umo09R6cfnwXZlrQ"><img src="https://img.shields.io/badge/PDF下载-代码随想录-blueviolet" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw"><img src="https://img.shields.io/badge/刷题-微信群-green" alt=""></a>
|
||||
<a href="https://img-blog.csdnimg.cn/20201210231711160.png"><img src="https://img.shields.io/badge/公众号-代码随想录-brightgreen" alt=""></a>
|
||||
<a href="https://space.bilibili.com/525438321"><img src="https://img.shields.io/badge/B站-代码随想录-orange" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
</p>
|
||||
<p align="center"><strong>欢迎大家参与本项目，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
<p align="center"><strong>欢迎大家<a href="https://mp.weixin.qq.com/s/tqCxrMEU-ajQumL1i8im9A">参与本项目</a>，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
|
||||
|
||||
## 55. 跳跃游戏
|
||||
@ -122,6 +122,24 @@ class Solution:
|
||||
```
|
||||
|
||||
Go：
|
||||
```Go
|
||||
func canJUmp(nums []int) bool {
|
||||
if len(nums)<=1{
|
||||
return true
|
||||
}
|
||||
dp:=make([]bool,len(nums))
|
||||
dp[0]=true
|
||||
for i:=1;i<len(nums);i++{
|
||||
for j:=i-1;j>=0;j--{
|
||||
if dp[j]&&nums[j]+j>=i{
|
||||
dp[i]=true
|
||||
break
|
||||
}
|
||||
}
|
||||
}
|
||||
return dp[len(nums)-1]
|
||||
}
|
||||
```
|
||||
|
||||
|
||||
|
||||
|
||||
@ -1,10 +1,10 @@
|
||||
<p align="center">
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/RsdcQ9umo09R6cfnwXZlrQ"><img src="https://img.shields.io/badge/PDF下载-代码随想录-blueviolet" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw"><img src="https://img.shields.io/badge/刷题-微信群-green" alt=""></a>
|
||||
<a href="https://img-blog.csdnimg.cn/20201210231711160.png"><img src="https://img.shields.io/badge/公众号-代码随想录-brightgreen" alt=""></a>
|
||||
<a href="https://space.bilibili.com/525438321"><img src="https://img.shields.io/badge/B站-代码随想录-orange" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
</p>
|
||||
<p align="center"><strong>欢迎大家参与本项目，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
<p align="center"><strong>欢迎大家<a href="https://mp.weixin.qq.com/s/tqCxrMEU-ajQumL1i8im9A">参与本项目</a>，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
|
||||
|
||||
## 56. 合并区间
|
||||
@ -168,10 +168,49 @@ class Solution {
|
||||
```
|
||||
|
||||
Python：
|
||||
|
||||
```python
|
||||
class Solution:
|
||||
def merge(self, intervals: List[List[int]]) -> List[List[int]]:
|
||||
if len(intervals) == 0: return intervals
|
||||
intervals.sort(key=lambda x: x[0])
|
||||
result = []
|
||||
result.append(intervals[0])
|
||||
for i in range(1, len(intervals)):
|
||||
last = result[-1]
|
||||
if last[1] >= intervals[i][0]:
|
||||
result[-1] = [last[0], max(last[1], intervals[i][1])]
|
||||
else:
|
||||
result.append(intervals[i])
|
||||
return result
|
||||
```
|
||||
|
||||
Go：
|
||||
```Go
|
||||
func merge(intervals [][]int) [][]int {
|
||||
sort.Slice(intervals, func(i, j int) bool {
|
||||
return intervals[i][0]<intervals[j][0]
|
||||
})
|
||||
|
||||
res:=[][]int{}
|
||||
prev:=intervals[0]
|
||||
|
||||
for i:=1;i<len(intervals);i++{
|
||||
cur :=intervals[i]
|
||||
if prev[1]<cur[0]{
|
||||
res=append(res,prev)
|
||||
prev=cur
|
||||
}else {
|
||||
prev[1]=max(prev[1],cur[1])
|
||||
}
|
||||
}
|
||||
res=append(res,prev)
|
||||
return res
|
||||
}
|
||||
func max(a, b int) int {
|
||||
if a > b { return a }
|
||||
return b
|
||||
}
|
||||
```
|
||||
|
||||
|
||||
|
||||
@ -179,4 +218,4 @@ Go：
|
||||
* 作者微信：[程序员Carl](https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw)
|
||||
* B站视频：[代码随想录](https://space.bilibili.com/525438321)
|
||||
* 知识星球：[代码随想录](https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ)
|
||||
<div align="center"><img src=../pics/公众号.png width=450 alt=> </img></div>
|
||||
<div align="center"><img src=../pics/公众号.png width=450 alt=> </img></div>
|
||||
|
||||
@ -1,10 +1,10 @@
|
||||
<p align="center">
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/RsdcQ9umo09R6cfnwXZlrQ"><img src="https://img.shields.io/badge/PDF下载-代码随想录-blueviolet" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw"><img src="https://img.shields.io/badge/刷题-微信群-green" alt=""></a>
|
||||
<a href="https://img-blog.csdnimg.cn/20201210231711160.png"><img src="https://img.shields.io/badge/公众号-代码随想录-brightgreen" alt=""></a>
|
||||
<a href="https://space.bilibili.com/525438321"><img src="https://img.shields.io/badge/B站-代码随想录-orange" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
</p>
|
||||
<p align="center"><strong>欢迎大家参与本项目，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
<p align="center"><strong>欢迎大家<a href="https://mp.weixin.qq.com/s/tqCxrMEU-ajQumL1i8im9A">参与本项目</a>，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
|
||||
|
||||
|
||||
@ -224,6 +224,49 @@ class Solution:
|
||||
return matrix
|
||||
```
|
||||
|
||||
javaScript
|
||||
|
||||
```js
|
||||
|
||||
/**
|
||||
* @param {number} n
|
||||
* @return {number[][]}
|
||||
*/
|
||||
var generateMatrix = function(n) {
|
||||
// new Array(n).fill(new Array(n))
|
||||
// 使用fill --> 填充的是同一个数组地址
|
||||
const res = Array.from({length: n}).map(() => new Array(n));
|
||||
let loop = n >> 1, i = 0, //循环次数
|
||||
count = 1,
|
||||
startX = startY = 0; // 起始位置
|
||||
while(++i <= loop) {
|
||||
// 定义行列
|
||||
let row = startX, column = startY;
|
||||
// [ startY, n - i)
|
||||
while(column < n - i) {
|
||||
res[row][column++] = count++;
|
||||
}
|
||||
// [ startX, n - i)
|
||||
while(row < n - i) {
|
||||
res[row++][column] = count++;
|
||||
}
|
||||
// [n - i , startY)
|
||||
while(column > startY) {
|
||||
res[row][column--] = count++;
|
||||
}
|
||||
// [n - i , startX)
|
||||
while(row > startX) {
|
||||
res[row--][column] = count++;
|
||||
}
|
||||
startX = ++startY;
|
||||
}
|
||||
if(n & 1) {
|
||||
res[startX][startY] = count;
|
||||
}
|
||||
return res;
|
||||
};
|
||||
```
|
||||
|
||||
|
||||
|
||||
-----------------------
|
||||
|
||||
@ -1,10 +1,10 @@
|
||||
<p align="center">
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/RsdcQ9umo09R6cfnwXZlrQ"><img src="https://img.shields.io/badge/PDF下载-代码随想录-blueviolet" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw"><img src="https://img.shields.io/badge/刷题-微信群-green" alt=""></a>
|
||||
<a href="https://img-blog.csdnimg.cn/20201210231711160.png"><img src="https://img.shields.io/badge/公众号-代码随想录-brightgreen" alt=""></a>
|
||||
<a href="https://space.bilibili.com/525438321"><img src="https://img.shields.io/badge/B站-代码随想录-orange" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
</p>
|
||||
<p align="center"><strong>欢迎大家参与本项目，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
<p align="center"><strong>欢迎大家<a href="https://mp.weixin.qq.com/s/tqCxrMEU-ajQumL1i8im9A">参与本项目</a>，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
|
||||
## 62.不同路径
|
||||
|
||||
@ -249,7 +249,24 @@ Python：
|
||||
|
||||
|
||||
Go：
|
||||
|
||||
```Go
|
||||
func uniquePaths(m int, n int) int {
|
||||
dp := make([][]int, m)
|
||||
for i := range dp {
|
||||
dp[i] = make([]int, n)
|
||||
dp[i][0] = 1
|
||||
}
|
||||
for j := 0; j < n; j++ {
|
||||
dp[0][j] = 1
|
||||
}
|
||||
for i := 1; i < m; i++ {
|
||||
for j := 1; j < n; j++ {
|
||||
dp[i][j] = dp[i-1][j] + dp[i][j-1]
|
||||
}
|
||||
}
|
||||
return dp[m-1][n-1]
|
||||
}
|
||||
```
|
||||
|
||||
|
||||
|
||||
|
||||
@ -1,10 +1,10 @@
|
||||
<p align="center">
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/RsdcQ9umo09R6cfnwXZlrQ"><img src="https://img.shields.io/badge/PDF下载-代码随想录-blueviolet" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw"><img src="https://img.shields.io/badge/刷题-微信群-green" alt=""></a>
|
||||
<a href="https://img-blog.csdnimg.cn/20201210231711160.png"><img src="https://img.shields.io/badge/公众号-代码随想录-brightgreen" alt=""></a>
|
||||
<a href="https://space.bilibili.com/525438321"><img src="https://img.shields.io/badge/B站-代码随想录-orange" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
</p>
|
||||
<p align="center"><strong>欢迎大家参与本项目，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
<p align="center"><strong>欢迎大家<a href="https://mp.weixin.qq.com/s/tqCxrMEU-ajQumL1i8im9A">参与本项目</a>，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
|
||||
## 63. 不同路径 II
|
||||
|
||||
@ -157,8 +157,6 @@ public:
|
||||
* 时间复杂度O(n * m) n m 分别为obstacleGrid 长度和宽度
|
||||
* 空间复杂度O(n * m)
|
||||
|
||||
至于能不能优化空间降为一维dp数组，我感觉不太行，因为要考虑障碍，如果把这些障碍压缩到一行，结果一定就不一样了。
|
||||
|
||||
## 总结
|
||||
|
||||
本题是[62.不同路径](https://mp.weixin.qq.com/s/MGgGIt4QCpFMROE9X9he_A)的障碍版，整体思路大体一致。
|
||||
|
||||
@ -1,10 +1,10 @@
|
||||
<p align="center">
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/RsdcQ9umo09R6cfnwXZlrQ"><img src="https://img.shields.io/badge/PDF下载-代码随想录-blueviolet" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw"><img src="https://img.shields.io/badge/刷题-微信群-green" alt=""></a>
|
||||
<a href="https://img-blog.csdnimg.cn/20201210231711160.png"><img src="https://img.shields.io/badge/公众号-代码随想录-brightgreen" alt=""></a>
|
||||
<a href="https://space.bilibili.com/525438321"><img src="https://img.shields.io/badge/B站-代码随想录-orange" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
</p>
|
||||
<p align="center"><strong>欢迎大家参与本项目，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
<p align="center"><strong>欢迎大家<a href="https://mp.weixin.qq.com/s/tqCxrMEU-ajQumL1i8im9A">参与本项目</a>，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
|
||||
## 70. 爬楼梯
|
||||
|
||||
|
||||
@ -1,10 +1,10 @@
|
||||
<p align="center">
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/RsdcQ9umo09R6cfnwXZlrQ"><img src="https://img.shields.io/badge/PDF下载-代码随想录-blueviolet" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw"><img src="https://img.shields.io/badge/刷题-微信群-green" alt=""></a>
|
||||
<a href="https://img-blog.csdnimg.cn/20201210231711160.png"><img src="https://img.shields.io/badge/公众号-代码随想录-brightgreen" alt=""></a>
|
||||
<a href="https://space.bilibili.com/525438321"><img src="https://img.shields.io/badge/B站-代码随想录-orange" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
</p>
|
||||
<p align="center"><strong>欢迎大家参与本项目，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
<p align="center"><strong>欢迎大家<a href="https://mp.weixin.qq.com/s/tqCxrMEU-ajQumL1i8im9A">参与本项目</a>，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
# 动态规划：以前我没得选，现在我选择再爬一次！
|
||||
|
||||
之前讲这道题目的时候，因为还没有讲背包问题，所以就只是讲了一下爬楼梯最直接的动规方法（斐波那契）。
|
||||
@ -157,4 +157,4 @@ Go：
|
||||
* 作者微信：[程序员Carl](https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw)
|
||||
* B站视频：[代码随想录](https://space.bilibili.com/525438321)
|
||||
* 知识星球：[代码随想录](https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ)
|
||||
<div align="center"><img src=../pics/公众号.png width=450 alt=> </img></div>
|
||||
<div align="center"><img src=../pics/公众号.png width=450 alt=> </img></div>
|
||||
|
||||
@ -1,10 +1,10 @@
|
||||
<p align="center">
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/RsdcQ9umo09R6cfnwXZlrQ"><img src="https://img.shields.io/badge/PDF下载-代码随想录-blueviolet" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw"><img src="https://img.shields.io/badge/刷题-微信群-green" alt=""></a>
|
||||
<a href="https://img-blog.csdnimg.cn/20201210231711160.png"><img src="https://img.shields.io/badge/公众号-代码随想录-brightgreen" alt=""></a>
|
||||
<a href="https://space.bilibili.com/525438321"><img src="https://img.shields.io/badge/B站-代码随想录-orange" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
</p>
|
||||
<p align="center"><strong>欢迎大家参与本项目，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
<p align="center"><strong>欢迎大家<a href="https://mp.weixin.qq.com/s/tqCxrMEU-ajQumL1i8im9A">参与本项目</a>，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
|
||||
## 72. 编辑距离
|
||||
|
||||
|
||||
@ -1,10 +1,10 @@
|
||||
<p align="center">
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/RsdcQ9umo09R6cfnwXZlrQ"><img src="https://img.shields.io/badge/PDF下载-代码随想录-blueviolet" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw"><img src="https://img.shields.io/badge/刷题-微信群-green" alt=""></a>
|
||||
<a href="https://img-blog.csdnimg.cn/20201210231711160.png"><img src="https://img.shields.io/badge/公众号-代码随想录-brightgreen" alt=""></a>
|
||||
<a href="https://space.bilibili.com/525438321"><img src="https://img.shields.io/badge/B站-代码随想录-orange" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
</p>
|
||||
<p align="center"><strong>欢迎大家参与本项目，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
<p align="center"><strong>欢迎大家<a href="https://mp.weixin.qq.com/s/tqCxrMEU-ajQumL1i8im9A">参与本项目</a>，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
|
||||
|
||||
|
||||
@ -370,8 +370,45 @@ class Solution {
|
||||
|
||||
|
||||
Python：
|
||||
```python
|
||||
class Solution:
|
||||
result: List[List[int]] = []
|
||||
path: List[int] = []
|
||||
def combine(self, n: int, k: int) -> List[List[int]]:
|
||||
self.result = []
|
||||
self.combineHelper(n, k, 1)
|
||||
return self.result
|
||||
|
||||
|
||||
def combineHelper(self, n: int, k: int, startIndex: int):
|
||||
if (l := len(self.path)) == k:
|
||||
self.result.append(self.path.copy())
|
||||
return
|
||||
for i in range(startIndex, n - (k - l) + 2):
|
||||
self.path.append(i)
|
||||
self.combineHelper(n, k, i + 1)
|
||||
self.path.pop()
|
||||
```
|
||||
javascript
|
||||
```javascript
|
||||
let result = []
|
||||
let path = []
|
||||
var combine = function(n, k) {
|
||||
result = []
|
||||
combineHelper(n, k, 1)
|
||||
return result
|
||||
};
|
||||
const combineHelper = (n, k, startIndex) => {
|
||||
if (path.length === k) {
|
||||
result.push([...path])
|
||||
return
|
||||
}
|
||||
for (let i = startIndex; i <= n - (k - path.length) + 1; ++i) {
|
||||
path.push(i)
|
||||
combineHelper(n, k, i + 1)
|
||||
path.pop()
|
||||
}
|
||||
}
|
||||
```
|
||||
Go：
|
||||
```Go
|
||||
var res [][]int
|
||||
@ -392,7 +429,7 @@ func backtrack(n,k,start int,track []int){
|
||||
if len(track)+n-start+1 < k {
|
||||
return
|
||||
}
|
||||
for i:=start;i<=n;i++{
|
||||
for i:=start;i<=n;i++{
|
||||
track=append(track,i)
|
||||
backtrack(n,k,i+1,track)
|
||||
track=track[:len(track)-1]
|
||||
@ -401,7 +438,6 @@ func backtrack(n,k,start int,track []int){
|
||||
```
|
||||
|
||||
|
||||
|
||||
-----------------------
|
||||
* 作者微信：[程序员Carl](https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw)
|
||||
* B站视频：[代码随想录](https://space.bilibili.com/525438321)
|
||||
|
||||
@ -1,10 +1,10 @@
|
||||
<p align="center">
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/RsdcQ9umo09R6cfnwXZlrQ"><img src="https://img.shields.io/badge/PDF下载-代码随想录-blueviolet" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw"><img src="https://img.shields.io/badge/刷题-微信群-green" alt=""></a>
|
||||
<a href="https://img-blog.csdnimg.cn/20201210231711160.png"><img src="https://img.shields.io/badge/公众号-代码随想录-brightgreen" alt=""></a>
|
||||
<a href="https://space.bilibili.com/525438321"><img src="https://img.shields.io/badge/B站-代码随想录-orange" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
</p>
|
||||
<p align="center"><strong>欢迎大家参与本项目，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
<p align="center"><strong>欢迎大家<a href="https://mp.weixin.qq.com/s/tqCxrMEU-ajQumL1i8im9A">参与本项目</a>，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
|
||||
|
||||
|
||||
|
||||
@ -1,10 +1,10 @@
|
||||
<p align="center">
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/RsdcQ9umo09R6cfnwXZlrQ"><img src="https://img.shields.io/badge/PDF下载-代码随想录-blueviolet" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw"><img src="https://img.shields.io/badge/刷题-微信群-green" alt=""></a>
|
||||
<a href="https://img-blog.csdnimg.cn/20201210231711160.png"><img src="https://img.shields.io/badge/公众号-代码随想录-brightgreen" alt=""></a>
|
||||
<a href="https://space.bilibili.com/525438321"><img src="https://img.shields.io/badge/B站-代码随想录-orange" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
</p>
|
||||
<p align="center"><strong>欢迎大家参与本项目，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
<p align="center"><strong>欢迎大家<a href="https://mp.weixin.qq.com/s/tqCxrMEU-ajQumL1i8im9A">参与本项目</a>，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
|
||||
|
||||
## 第78题. 子集
|
||||
|
||||
@ -1,10 +1,10 @@
|
||||
<p align="center">
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/RsdcQ9umo09R6cfnwXZlrQ"><img src="https://img.shields.io/badge/PDF下载-代码随想录-blueviolet" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw"><img src="https://img.shields.io/badge/刷题-微信群-green" alt=""></a>
|
||||
<a href="https://img-blog.csdnimg.cn/20201210231711160.png"><img src="https://img.shields.io/badge/公众号-代码随想录-brightgreen" alt=""></a>
|
||||
<a href="https://space.bilibili.com/525438321"><img src="https://img.shields.io/badge/B站-代码随想录-orange" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
</p>
|
||||
<p align="center"><strong>欢迎大家参与本项目，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
<p align="center"><strong>欢迎大家<a href="https://mp.weixin.qq.com/s/tqCxrMEU-ajQumL1i8im9A">参与本项目</a>，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
|
||||
|
||||
## 第90题.子集II
|
||||
|
||||
@ -1,10 +1,10 @@
|
||||
<p align="center">
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/RsdcQ9umo09R6cfnwXZlrQ"><img src="https://img.shields.io/badge/PDF下载-代码随想录-blueviolet" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw"><img src="https://img.shields.io/badge/刷题-微信群-green" alt=""></a>
|
||||
<a href="https://img-blog.csdnimg.cn/20201210231711160.png"><img src="https://img.shields.io/badge/公众号-代码随想录-brightgreen" alt=""></a>
|
||||
<a href="https://space.bilibili.com/525438321"><img src="https://img.shields.io/badge/B站-代码随想录-orange" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
</p>
|
||||
<p align="center"><strong>欢迎大家参与本项目，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
<p align="center"><strong>欢迎大家<a href="https://mp.weixin.qq.com/s/tqCxrMEU-ajQumL1i8im9A">参与本项目</a>，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
|
||||
|
||||
|
||||
|
||||
@ -1,10 +1,10 @@
|
||||
<p align="center">
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/RsdcQ9umo09R6cfnwXZlrQ"><img src="https://img.shields.io/badge/PDF下载-代码随想录-blueviolet" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw"><img src="https://img.shields.io/badge/刷题-微信群-green" alt=""></a>
|
||||
<a href="https://img-blog.csdnimg.cn/20201210231711160.png"><img src="https://img.shields.io/badge/公众号-代码随想录-brightgreen" alt=""></a>
|
||||
<a href="https://space.bilibili.com/525438321"><img src="https://img.shields.io/badge/B站-代码随想录-orange" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
</p>
|
||||
<p align="center"><strong>欢迎大家参与本项目，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
<p align="center"><strong>欢迎大家<a href="https://mp.weixin.qq.com/s/tqCxrMEU-ajQumL1i8im9A">参与本项目</a>，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
|
||||
## 96.不同的二叉搜索树
|
||||
|
||||
@ -189,7 +189,18 @@ Python：
|
||||
|
||||
|
||||
Go：
|
||||
|
||||
```Go
|
||||
func numTrees(n int)int{
|
||||
dp:=make([]int,n+1)
|
||||
dp[0]=1
|
||||
for i:=1;i<=n;i++{
|
||||
for j:=1;j<=i;j++{
|
||||
dp[i]+=dp[j-1]*dp[i-j]
|
||||
}
|
||||
}
|
||||
return dp[n]
|
||||
}
|
||||
```
|
||||
|
||||
|
||||
|
||||
|
||||
@ -1,10 +1,10 @@
|
||||
<p align="center">
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/RsdcQ9umo09R6cfnwXZlrQ"><img src="https://img.shields.io/badge/PDF下载-代码随想录-blueviolet" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw"><img src="https://img.shields.io/badge/刷题-微信群-green" alt=""></a>
|
||||
<a href="https://img-blog.csdnimg.cn/20201210231711160.png"><img src="https://img.shields.io/badge/公众号-代码随想录-brightgreen" alt=""></a>
|
||||
<a href="https://space.bilibili.com/525438321"><img src="https://img.shields.io/badge/B站-代码随想录-orange" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
</p>
|
||||
<p align="center"><strong>欢迎大家参与本项目，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
<p align="center"><strong>欢迎大家<a href="https://mp.weixin.qq.com/s/tqCxrMEU-ajQumL1i8im9A">参与本项目</a>，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
|
||||
|
||||
## 98.验证二叉搜索树
|
||||
@ -336,8 +336,26 @@ class Solution {
|
||||
```
|
||||
|
||||
Python：
|
||||
|
||||
|
||||
```python
|
||||
# Definition for a binary tree node.
|
||||
# class TreeNode:
|
||||
# def __init__(self, val=0, left=None, right=None):
|
||||
# self.val = val
|
||||
# self.left = left
|
||||
# self.right = right
|
||||
//递归法
|
||||
class Solution:
|
||||
def isValidBST(self, root: TreeNode) -> bool:
|
||||
res = [] //把二叉搜索树按中序遍历写成list
|
||||
def buildalist(root):
|
||||
if not root: return
|
||||
buildalist(root.left) //左
|
||||
res.append(root.val) //中
|
||||
buildalist(root.right) //右
|
||||
return res
|
||||
buildalist(root)
|
||||
return res == sorted(res) and len(set(res)) == len(res) //检查list里的数有没有重复元素，以及是否按从小到大排列
|
||||
```
|
||||
Go：
|
||||
```Go
|
||||
import "math"
|
||||
@ -365,4 +383,4 @@ func isBST(root *TreeNode, min, max int) bool {
|
||||
* 作者微信：[程序员Carl](https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw)
|
||||
* B站视频：[代码随想录](https://space.bilibili.com/525438321)
|
||||
* 知识星球：[代码随想录](https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ)
|
||||
<div align="center"><img src=../pics/公众号.png width=450 alt=> </img></div>
|
||||
<div align="center"><img src=../pics/公众号.png width=450 alt=> </img></div>
|
||||
|
||||
@ -1,10 +1,10 @@
|
||||
<p align="center">
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/RsdcQ9umo09R6cfnwXZlrQ"><img src="https://img.shields.io/badge/PDF下载-代码随想录-blueviolet" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw"><img src="https://img.shields.io/badge/刷题-微信群-green" alt=""></a>
|
||||
<a href="https://img-blog.csdnimg.cn/20201210231711160.png"><img src="https://img.shields.io/badge/公众号-代码随想录-brightgreen" alt=""></a>
|
||||
<a href="https://space.bilibili.com/525438321"><img src="https://img.shields.io/badge/B站-代码随想录-orange" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
</p>
|
||||
<p align="center"><strong>欢迎大家参与本项目，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
<p align="center"><strong>欢迎大家<a href="https://mp.weixin.qq.com/s/tqCxrMEU-ajQumL1i8im9A">参与本项目</a>，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
|
||||
|
||||
## 101. 对称二叉树
|
||||
|
||||
@ -1,10 +1,10 @@
|
||||
<p align="center">
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/RsdcQ9umo09R6cfnwXZlrQ"><img src="https://img.shields.io/badge/PDF下载-代码随想录-blueviolet" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw"><img src="https://img.shields.io/badge/刷题-微信群-green" alt=""></a>
|
||||
<a href="https://img-blog.csdnimg.cn/20201210231711160.png"><img src="https://img.shields.io/badge/公众号-代码随想录-brightgreen" alt=""></a>
|
||||
<a href="https://space.bilibili.com/525438321"><img src="https://img.shields.io/badge/B站-代码随想录-orange" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
</p>
|
||||
<p align="center"><strong>欢迎大家参与本项目，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
<p align="center"><strong>欢迎大家<a href="https://mp.weixin.qq.com/s/tqCxrMEU-ajQumL1i8im9A">参与本项目</a>，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
|
||||
# 二叉树的层序遍历
|
||||
|
||||
@ -79,6 +79,35 @@ public:
|
||||
return result;
|
||||
}
|
||||
};
|
||||
```
|
||||
javascript代码：
|
||||
|
||||
```javascript
|
||||
var levelOrder = function(root) {
|
||||
//二叉树的层序遍历
|
||||
let res=[],queue=[];
|
||||
queue.push(root);
|
||||
if(root===null){
|
||||
return res;
|
||||
}
|
||||
while(queue.length!==0){
|
||||
// 记录当前层级节点数
|
||||
let length=queue.length;
|
||||
//存放每一层的节点
|
||||
let curLevel=[];
|
||||
for(let i=0;i<length;i++){
|
||||
let node=queue.shift();
|
||||
curLevel.push(node.val);
|
||||
// 存放当前层下一层的节点
|
||||
node.left&&queue.push(node.left);
|
||||
node.right&&queue.push(node.right);
|
||||
}
|
||||
//把每一层的结果放到结果数组
|
||||
res.push(curLevel);
|
||||
}
|
||||
return res;
|
||||
};
|
||||
|
||||
```
|
||||
|
||||
**此时我们就掌握了二叉树的层序遍历了，那么如下五道leetcode上的题目，只需要修改模板的一两行代码（不能再多了），便可打倒！**
|
||||
@ -122,6 +151,30 @@ public:
|
||||
}
|
||||
};
|
||||
```
|
||||
javascript代码
|
||||
|
||||
```javascript
|
||||
var levelOrderBottom = function(root) {
|
||||
let res=[],queue=[];
|
||||
queue.push(root);
|
||||
while(queue.length&&root!==null){
|
||||
// 存放当前层级节点数组
|
||||
let curLevel=[];
|
||||
// 计算当前层级节点数量
|
||||
let length=queue.length;
|
||||
while(length--){
|
||||
let node=queue.shift();
|
||||
// 把当前层节点存入curLevel数组
|
||||
curLevel.push(node.val);
|
||||
// 把下一层级的左右节点存入queue队列
|
||||
node.left&&queue.push(node.left);
|
||||
node.right&&queue.push(node.right);
|
||||
}
|
||||
res.push(curLevel);
|
||||
}
|
||||
return res.reverse();
|
||||
};
|
||||
```
|
||||
|
||||
|
||||
## 199.二叉树的右视图
|
||||
@ -159,6 +212,29 @@ public:
|
||||
}
|
||||
};
|
||||
```
|
||||
javascript代码:
|
||||
|
||||
```javascript
|
||||
var rightSideView = function(root) {
|
||||
//二叉树右视图 只需要把每一层最后一个节点存储到res数组
|
||||
let res=[],queue=[];
|
||||
queue.push(root);
|
||||
while(queue.length&&root!==null){
|
||||
// 记录当前层级节点个数
|
||||
let length=queue.length;
|
||||
while(length--){
|
||||
let node=queue.shift();
|
||||
//length长度为0的时候表明到了层级最后一个节点
|
||||
if(!length){
|
||||
res.push(node.val);
|
||||
}
|
||||
node.left&&queue.push(node.left);
|
||||
node.right&&queue.push(node.right);
|
||||
}
|
||||
}
|
||||
return res;
|
||||
};
|
||||
```
|
||||
|
||||
## 637.二叉树的层平均值
|
||||
|
||||
@ -199,6 +275,31 @@ public:
|
||||
|
||||
```
|
||||
|
||||
javascript代码：
|
||||
|
||||
```javascript
|
||||
var averageOfLevels = function(root) {
|
||||
//层级平均值
|
||||
let res=[],queue=[];
|
||||
queue.push(root);
|
||||
while(queue.length&&root!==null){
|
||||
//每一层节点个数
|
||||
let length=queue.length;
|
||||
//sum记录每一层的和
|
||||
let sum=0;
|
||||
for(let i=0;i<length;i++){
|
||||
let node=queue.shift();
|
||||
sum+=node.val;
|
||||
node.left&&queue.push(node.left);
|
||||
node.right&&queue.push(node.right);
|
||||
}
|
||||
//每一层的平均值存入数组res
|
||||
res.push(sum/length);
|
||||
}
|
||||
return res;
|
||||
};
|
||||
```
|
||||
|
||||
## 429.N叉树的层序遍历
|
||||
|
||||
题目链接：https://leetcode-cn.com/problems/n-ary-tree-level-order-traversal/
|
||||
@ -250,6 +351,31 @@ public:
|
||||
};
|
||||
```
|
||||
|
||||
JavaScript代码：
|
||||
```JavaScript
|
||||
var levelOrder = function(root) {
|
||||
//每一层可能有2个以上,所以不再使用node.left node.right
|
||||
let res=[],queue=[];
|
||||
queue.push(root);
|
||||
while(queue.length&&root!==null){
|
||||
//记录每一层节点个数还是和二叉树一致
|
||||
let length=queue.length;
|
||||
//存放每层节点 也和二叉树一致
|
||||
let curLevel=[];
|
||||
while(length--){
|
||||
let node = queue.shift();
|
||||
curLevel.push(node.val);
|
||||
//这里不再是 ndoe.left node.right 而是循坏node.children
|
||||
for(let item of node.children){
|
||||
item&&queue.push(item);
|
||||
}
|
||||
}
|
||||
res.push(curLevel);
|
||||
}
|
||||
return res;
|
||||
};
|
||||
```
|
||||
|
||||
## 515.在每个树行中找最大值
|
||||
|
||||
题目链接：https://leetcode-cn.com/problems/find-largest-value-in-each-tree-row/
|
||||
@ -287,6 +413,29 @@ public:
|
||||
}
|
||||
};
|
||||
```
|
||||
javascript代码：
|
||||
|
||||
```javascript
|
||||
var largestValues = function(root) {
|
||||
//使用层序遍历
|
||||
let res=[],queue=[];
|
||||
queue.push(root);
|
||||
while(root!==null&&queue.length){
|
||||
//设置max初始值就是队列的第一个元素
|
||||
let max=queue[0];
|
||||
let length=queue.length;
|
||||
while(length--){
|
||||
let node = queue.shift();
|
||||
max=max>node.val?max:node.val;
|
||||
node.left&&queue.push(node.left);
|
||||
node.right&&queue.push(node.right);
|
||||
}
|
||||
//把每一层的最大值放到res数组
|
||||
res.push(max);
|
||||
}
|
||||
return res;
|
||||
};
|
||||
```
|
||||
|
||||
## 116.填充每个节点的下一个右侧节点指针
|
||||
|
||||
@ -657,8 +806,56 @@ Python：
|
||||
|
||||
|
||||
Go：
|
||||
```Go
|
||||
func levelOrder(root *TreeNode) [][]int {
|
||||
result:=make([][]int,0)
|
||||
if root==nil{
|
||||
return result
|
||||
}
|
||||
|
||||
queue:=make([]*TreeNode,0)
|
||||
queue=append(queue,root)
|
||||
|
||||
for len(queue)>0{
|
||||
list:=make([]int,0)
|
||||
l:=len(queue)
|
||||
|
||||
for i:=0;i<l;i++{
|
||||
level:=queue[0]
|
||||
queue=queue[1:]
|
||||
list=append(list,level.Val)
|
||||
if level.Left!=nil{
|
||||
queue=append(queue,level.Left)
|
||||
}
|
||||
if level.Right!=nil{
|
||||
queue=append(queue,level.Right)
|
||||
}
|
||||
}
|
||||
result=append(result,list)
|
||||
}
|
||||
return result
|
||||
}
|
||||
```
|
||||
Javascript:
|
||||
```javascript
|
||||
var levelOrder = function (root) {
|
||||
let ans = [];
|
||||
if (!root) return ans;
|
||||
let queue = [root];
|
||||
while (queue.length) {
|
||||
let size = queue.length;
|
||||
let temp = [];
|
||||
while (size--) {
|
||||
let n = queue.shift();
|
||||
temp.push(n.val);
|
||||
if (n.left) queue.push(n.left);
|
||||
if (n.right) queue.push(n.right);
|
||||
}
|
||||
ans.push(temp);
|
||||
}
|
||||
return ans;
|
||||
};
|
||||
```
|
||||
|
||||
-----------------------
|
||||
* 作者微信：[程序员Carl](https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw)
|
||||
|
||||
@ -1,10 +1,10 @@
|
||||
<p align="center">
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/RsdcQ9umo09R6cfnwXZlrQ"><img src="https://img.shields.io/badge/PDF下载-代码随想录-blueviolet" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw"><img src="https://img.shields.io/badge/刷题-微信群-green" alt=""></a>
|
||||
<a href="https://img-blog.csdnimg.cn/20201210231711160.png"><img src="https://img.shields.io/badge/公众号-代码随想录-brightgreen" alt=""></a>
|
||||
<a href="https://space.bilibili.com/525438321"><img src="https://img.shields.io/badge/B站-代码随想录-orange" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
</p>
|
||||
<p align="center"><strong>欢迎大家参与本项目，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
<p align="center"><strong>欢迎大家<a href="https://mp.weixin.qq.com/s/tqCxrMEU-ajQumL1i8im9A">参与本项目</a>，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
|
||||
|
||||
看完本篇可以一起做了如下两道题目：
|
||||
@ -297,4 +297,4 @@ var maxDepth = function(root) {
|
||||
* 作者微信：[程序员Carl](https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw)
|
||||
* B站视频：[代码随想录](https://space.bilibili.com/525438321)
|
||||
* 知识星球：[代码随想录](https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ)
|
||||
<div align="center"><img src=../pics/公众号.png width=450 alt=> </img></div>
|
||||
<div align="center"><img src=../pics/公众号.png width=450 alt=> </img></div>
|
||||
|
||||
@ -1,10 +1,10 @@
|
||||
<p align="center">
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/RsdcQ9umo09R6cfnwXZlrQ"><img src="https://img.shields.io/badge/PDF下载-代码随想录-blueviolet" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw"><img src="https://img.shields.io/badge/刷题-微信群-green" alt=""></a>
|
||||
<a href="https://img-blog.csdnimg.cn/20201210231711160.png"><img src="https://img.shields.io/badge/公众号-代码随想录-brightgreen" alt=""></a>
|
||||
<a href="https://space.bilibili.com/525438321"><img src="https://img.shields.io/badge/B站-代码随想录-orange" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
</p>
|
||||
<p align="center"><strong>欢迎大家参与本项目，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
<p align="center"><strong>欢迎大家<a href="https://mp.weixin.qq.com/s/tqCxrMEU-ajQumL1i8im9A">参与本项目</a>，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
|
||||
|
||||
看完本文，可以一起解决如下两道题目
|
||||
@ -618,8 +618,42 @@ class Solution {
|
||||
```
|
||||
|
||||
Python：
|
||||
|
||||
|
||||
105.从前序与中序遍历序列构造二叉树
|
||||
```python
|
||||
# Definition for a binary tree node.
|
||||
# class TreeNode:
|
||||
# def __init__(self, val=0, left=None, right=None):
|
||||
# self.val = val
|
||||
# self.left = left
|
||||
# self.right = right
|
||||
//递归法
|
||||
class Solution:
|
||||
def buildTree(self, preorder: List[int], inorder: List[int]) -> TreeNode:
|
||||
if not preorder: return None //特殊情况
|
||||
root = TreeNode(preorder[0]) //新建父节点
|
||||
p=inorder.index(preorder[0]) //找到父节点在中序遍历的位置(因为没有重复的元素，才可以这样找)
|
||||
root.left = self.buildTree(preorder[1:p+1],inorder[:p]) //注意左节点时分割中序数组和前续数组的开闭环
|
||||
root.right = self.buildTree(preorder[p+1:],inorder[p+1:]) //分割中序数组和前续数组
|
||||
return root
|
||||
```
|
||||
106.从中序与后序遍历序列构造二叉树
|
||||
```python
|
||||
# Definition for a binary tree node.
|
||||
# class TreeNode:
|
||||
# def __init__(self, val=0, left=None, right=None):
|
||||
# self.val = val
|
||||
# self.left = left
|
||||
# self.right = right
|
||||
//递归法
|
||||
class Solution:
|
||||
def buildTree(self, inorder: List[int], postorder: List[int]) -> TreeNode:
|
||||
if not postorder: return None //特殊情况
|
||||
root = TreeNode(postorder[-1]) //新建父节点
|
||||
p=inorder.index(postorder[-1]) //找到父节点在中序遍历的位置*因为没有重复的元素，才可以这样找
|
||||
root.left = self.buildTree(inorder[:p],postorder[:p]) //分割中序数组和后续数组
|
||||
root.right = self.buildTree(inorder[p+1:],postorder[p:-1]) //注意右节点时分割中序数组和后续数组的开闭环
|
||||
return root
|
||||
```
|
||||
Go：
|
||||
|
||||
|
||||
@ -643,4 +677,4 @@ var buildTree = function(inorder, postorder) {
|
||||
* 作者微信：[程序员Carl](https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw)
|
||||
* B站视频：[代码随想录](https://space.bilibili.com/525438321)
|
||||
* 知识星球：[代码随想录](https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ)
|
||||
<div align="center"><img src=../pics/公众号.png width=450 alt=> </img></div>
|
||||
<div align="center"><img src=../pics/公众号.png width=450 alt=> </img></div>
|
||||
|
||||
@ -1,10 +1,10 @@
|
||||
<p align="center">
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/RsdcQ9umo09R6cfnwXZlrQ"><img src="https://img.shields.io/badge/PDF下载-代码随想录-blueviolet" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw"><img src="https://img.shields.io/badge/刷题-微信群-green" alt=""></a>
|
||||
<a href="https://img-blog.csdnimg.cn/20201210231711160.png"><img src="https://img.shields.io/badge/公众号-代码随想录-brightgreen" alt=""></a>
|
||||
<a href="https://space.bilibili.com/525438321"><img src="https://img.shields.io/badge/B站-代码随想录-orange" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
</p>
|
||||
<p align="center"><strong>欢迎大家参与本项目，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
<p align="center"><strong>欢迎大家<a href="https://mp.weixin.qq.com/s/tqCxrMEU-ajQumL1i8im9A">参与本项目</a>，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
|
||||
|
||||
> 构造二叉搜索树，一不小心就平衡了
|
||||
@ -233,7 +233,27 @@ class Solution {
|
||||
```
|
||||
|
||||
Python：
|
||||
|
||||
```python3
|
||||
# Definition for a binary tree node.
|
||||
# class TreeNode:
|
||||
# def __init__(self, val=0, left=None, right=None):
|
||||
# self.val = val
|
||||
# self.left = left
|
||||
# self.right = right
|
||||
#递归法
|
||||
class Solution:
|
||||
def sortedArrayToBST(self, nums: List[int]) -> TreeNode:
|
||||
def buildaTree(left,right):
|
||||
if left > right: return None #左闭右闭的区间，当区间 left > right的时候，就是空节点,当left = right的时候，不为空
|
||||
mid = left + (right - left) // 2 #保证数据不会越界
|
||||
val = nums[mid]
|
||||
root = TreeNode(val)
|
||||
root.left = buildaTree(left,mid - 1)
|
||||
root.right = buildaTree(mid + 1,right)
|
||||
return root
|
||||
root = buildaTree(0,len(nums) - 1) #左闭右闭区间
|
||||
return root
|
||||
```
|
||||
|
||||
Go：
|
||||
|
||||
@ -244,4 +264,4 @@ Go：
|
||||
* 作者微信：[程序员Carl](https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw)
|
||||
* B站视频：[代码随想录](https://space.bilibili.com/525438321)
|
||||
* 知识星球：[代码随想录](https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ)
|
||||
<div align="center"><img src=../pics/公众号.png width=450 alt=> </img></div>
|
||||
<div align="center"><img src=../pics/公众号.png width=450 alt=> </img></div>
|
||||
|
||||
@ -1,10 +1,10 @@
|
||||
<p align="center">
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/RsdcQ9umo09R6cfnwXZlrQ"><img src="https://img.shields.io/badge/PDF下载-代码随想录-blueviolet" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw"><img src="https://img.shields.io/badge/刷题-微信群-green" alt=""></a>
|
||||
<a href="https://img-blog.csdnimg.cn/20201210231711160.png"><img src="https://img.shields.io/badge/公众号-代码随想录-brightgreen" alt=""></a>
|
||||
<a href="https://space.bilibili.com/525438321"><img src="https://img.shields.io/badge/B站-代码随想录-orange" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
</p>
|
||||
<p align="center"><strong>欢迎大家参与本项目，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
<p align="center"><strong>欢迎大家<a href="https://mp.weixin.qq.com/s/tqCxrMEU-ajQumL1i8im9A">参与本项目</a>，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
|
||||
|
||||
> 求高度还是求深度，你搞懂了不？
|
||||
|
||||
@ -1,10 +1,10 @@
|
||||
<p align="center">
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/RsdcQ9umo09R6cfnwXZlrQ"><img src="https://img.shields.io/badge/PDF下载-代码随想录-blueviolet" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw"><img src="https://img.shields.io/badge/刷题-微信群-green" alt=""></a>
|
||||
<a href="https://img-blog.csdnimg.cn/20201210231711160.png"><img src="https://img.shields.io/badge/公众号-代码随想录-brightgreen" alt=""></a>
|
||||
<a href="https://space.bilibili.com/525438321"><img src="https://img.shields.io/badge/B站-代码随想录-orange" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
</p>
|
||||
<p align="center"><strong>欢迎大家参与本项目，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
<p align="center"><strong>欢迎大家<a href="https://mp.weixin.qq.com/s/tqCxrMEU-ajQumL1i8im9A">参与本项目</a>，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
|
||||
|
||||
> 和求最大深度一个套路？
|
||||
@ -302,6 +302,53 @@ class Solution:
|
||||
Go：
|
||||
|
||||
|
||||
JavaScript:
|
||||
|
||||
递归法：
|
||||
|
||||
```javascript
|
||||
/**
|
||||
* @param {TreeNode} root
|
||||
* @return {number}
|
||||
*/
|
||||
var minDepth1 = function(root) {
|
||||
if(!root) return 0;
|
||||
// 到叶子节点 返回 1
|
||||
if(!root.left && !root.right) return 1;
|
||||
// 只有右节点时 递归右节点
|
||||
if(!root.left) return 1 + minDepth(root.right);、
|
||||
// 只有左节点时 递归左节点
|
||||
if(!root.right) return 1 + minDepth(root.left);
|
||||
return Math.min(minDepth(root.left), minDepth(root.right)) + 1;
|
||||
};
|
||||
```
|
||||
|
||||
迭代法：
|
||||
|
||||
```javascript
|
||||
/**
|
||||
* @param {TreeNode} root
|
||||
* @return {number}
|
||||
*/
|
||||
var minDepth = function(root) {
|
||||
if(!root) return 0;
|
||||
const queue = [root];
|
||||
let dep = 0;
|
||||
while(true) {
|
||||
let size = queue.length;
|
||||
dep++;
|
||||
while(size--){
|
||||
const node = queue.shift();
|
||||
// 到第一个叶子节点 返回 当前深度
|
||||
if(!node.left && !node.right) return dep;
|
||||
node.left && queue.push(node.left);
|
||||
node.right && queue.push(node.right);
|
||||
}
|
||||
}
|
||||
};
|
||||
```
|
||||
|
||||
|
||||
|
||||
|
||||
-----------------------
|
||||
|
||||
@ -1,10 +1,10 @@
|
||||
<p align="center">
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/RsdcQ9umo09R6cfnwXZlrQ"><img src="https://img.shields.io/badge/PDF下载-代码随想录-blueviolet" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw"><img src="https://img.shields.io/badge/刷题-微信群-green" alt=""></a>
|
||||
<a href="https://img-blog.csdnimg.cn/20201210231711160.png"><img src="https://img.shields.io/badge/公众号-代码随想录-brightgreen" alt=""></a>
|
||||
<a href="https://space.bilibili.com/525438321"><img src="https://img.shields.io/badge/B站-代码随想录-orange" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
</p>
|
||||
<p align="center"><strong>欢迎大家参与本项目，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
<p align="center"><strong>欢迎大家<a href="https://mp.weixin.qq.com/s/tqCxrMEU-ajQumL1i8im9A">参与本项目</a>，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
|
||||
|
||||
> 递归函数什么时候需要返回值
|
||||
@ -349,6 +349,74 @@ class Solution {
|
||||
|
||||
Python：
|
||||
|
||||
0112.路径总和
|
||||
```python
|
||||
# Definition for a binary tree node.
|
||||
# class TreeNode:
|
||||
# def __init__(self, val=0, left=None, right=None):
|
||||
# self.val = val
|
||||
# self.left = left
|
||||
# self.right = right
|
||||
|
||||
// 递归法
|
||||
|
||||
class Solution:
|
||||
def hasPathSum(self, root: TreeNode, targetSum: int) -> bool:
|
||||
def isornot(root,targetSum)->bool:
|
||||
if (not root.left) and (not root.right) and targetSum == 0:return True // 遇到叶子节点，并且计数为0
|
||||
if (not root.left) and (not root.right):return False //遇到叶子节点，计数不为0
|
||||
if root.left:
|
||||
targetSum -= root.left.val //左节点
|
||||
if isornot(root.left,targetSum):return True //递归，处理左节点
|
||||
targetSum += root.left.val //回溯
|
||||
if root.right:
|
||||
targetSum -= root.right.val //右节点
|
||||
if isornot(root.right,targetSum):return True //递归，处理右节点
|
||||
targetSum += root.right.val //回溯
|
||||
return False
|
||||
|
||||
if root == None:return False //别忘记处理空TreeNode
|
||||
else:return isornot(root,targetSum-root.val)
|
||||
```
|
||||
|
||||
0113.路径总和-ii
|
||||
```python
|
||||
# Definition for a binary tree node.
|
||||
# class TreeNode:
|
||||
# def __init__(self, val=0, left=None, right=None):
|
||||
# self.val = val
|
||||
# self.left = left
|
||||
# self.right = right
|
||||
//递归法
|
||||
class Solution:
|
||||
def pathSum(self, root: TreeNode, targetSum: int) -> List[List[int]]:
|
||||
path=[]
|
||||
res=[]
|
||||
def pathes(root,targetSum):
|
||||
if (not root.left) and (not root.right) and targetSum == 0: // 遇到叶子节点，并且计数为0
|
||||
res.append(path[:]) //找到一种路径，记录到res中，注意必须是path[:]而不是path
|
||||
return
|
||||
if (not root.left) and (not root.right):return // 遇到叶子节点直接返回
|
||||
if root.left: //左
|
||||
targetSum -= root.left.val
|
||||
path.append(root.left.val) //递归前记录节点
|
||||
pathes(root.left,targetSum) //递归
|
||||
targetSum += root.left.val //回溯
|
||||
path.pop() //回溯
|
||||
if root.right: //右
|
||||
targetSum -= root.right.val
|
||||
path.append(root.right.val) //递归前记录节点
|
||||
pathes(root.right,targetSum) //递归
|
||||
targetSum += root.right.val //回溯
|
||||
path.pop() //回溯
|
||||
return
|
||||
|
||||
if root == None:return [] //处理空TreeNode
|
||||
else:
|
||||
path.append(root.val) //首先处理根节点
|
||||
pathes(root,targetSum-root.val)
|
||||
return res
|
||||
```
|
||||
|
||||
Go：
|
||||
|
||||
@ -427,4 +495,4 @@ let pathSum = function (root, targetSum) {
|
||||
* 作者微信：[程序员Carl](https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw)
|
||||
* B站视频：[代码随想录](https://space.bilibili.com/525438321)
|
||||
* 知识星球：[代码随想录](https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ)
|
||||
<div align="center"><img src=../pics/公众号.png width=450 alt=> </img></div>
|
||||
<div align="center"><img src=../pics/公众号.png width=450 alt=> </img></div>
|
||||
|
||||
@ -1,10 +1,10 @@
|
||||
<p align="center">
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/RsdcQ9umo09R6cfnwXZlrQ"><img src="https://img.shields.io/badge/PDF下载-代码随想录-blueviolet" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw"><img src="https://img.shields.io/badge/刷题-微信群-green" alt=""></a>
|
||||
<a href="https://img-blog.csdnimg.cn/20201210231711160.png"><img src="https://img.shields.io/badge/公众号-代码随想录-brightgreen" alt=""></a>
|
||||
<a href="https://space.bilibili.com/525438321"><img src="https://img.shields.io/badge/B站-代码随想录-orange" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
</p>
|
||||
<p align="center"><strong>欢迎大家参与本项目，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
<p align="center"><strong>欢迎大家<a href="https://mp.weixin.qq.com/s/tqCxrMEU-ajQumL1i8im9A">参与本项目</a>，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
|
||||
## 115.不同的子序列
|
||||
|
||||
|
||||
@ -1,10 +1,10 @@
|
||||
<p align="center">
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/RsdcQ9umo09R6cfnwXZlrQ"><img src="https://img.shields.io/badge/PDF下载-代码随想录-blueviolet" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw"><img src="https://img.shields.io/badge/刷题-微信群-green" alt=""></a>
|
||||
<a href="https://img-blog.csdnimg.cn/20201210231711160.png"><img src="https://img.shields.io/badge/公众号-代码随想录-brightgreen" alt=""></a>
|
||||
<a href="https://space.bilibili.com/525438321"><img src="https://img.shields.io/badge/B站-代码随想录-orange" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
</p>
|
||||
<p align="center"><strong>欢迎大家参与本项目，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
<p align="center"><strong>欢迎大家<a href="https://mp.weixin.qq.com/s/tqCxrMEU-ajQumL1i8im9A">参与本项目</a>，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
|
||||
## 121. 买卖股票的最佳时机
|
||||
|
||||
@ -196,9 +196,9 @@ public:
|
||||
|
||||
## 其他语言版本
|
||||
|
||||
|
||||
Java：
|
||||
```java
|
||||
// 贪心思路
|
||||
class Solution {
|
||||
public int maxProfit(int[] prices) {
|
||||
int minprice = Integer.MAX_VALUE;
|
||||
@ -215,10 +215,62 @@ class Solution {
|
||||
}
|
||||
```
|
||||
|
||||
``` java
|
||||
class Solution { // 动态规划解法
|
||||
public int maxProfit(int[] prices) {
|
||||
// 可交易次数
|
||||
int k = 1;
|
||||
// [天数][交易次数][是否持有股票]
|
||||
int[][][] dp = new int[prices.length][k + 1][2];
|
||||
|
||||
// bad case
|
||||
dp[0][0][0] = 0;
|
||||
dp[0][0][1] = Integer.MIN_VALUE;
|
||||
dp[0][1][0] = Integer.MIN_VALUE;
|
||||
dp[0][1][1] = -prices[0];
|
||||
|
||||
for (int i = 1; i < prices.length; i++) {
|
||||
for (int j = k; j >= 1; j--) {
|
||||
// dp公式
|
||||
dp[i][j][0] = Math.max(dp[i - 1][j][0], dp[i - 1][j][1] + prices[i]);
|
||||
dp[i][j][1] = Math.max(dp[i - 1][j][1], dp[i - 1][j - 1][0] - prices[i]);
|
||||
}
|
||||
}
|
||||
|
||||
return dp[prices.length - 1][k][0] > 0 ? dp[prices.length - 1][k][0] : 0;
|
||||
}
|
||||
}
|
||||
```
|
||||
|
||||
Python：
|
||||
|
||||
|
||||
Go：
|
||||
```Go
|
||||
func maxProfit(prices []int) int {
|
||||
length:=len(prices)
|
||||
if length==0{return 0}
|
||||
dp:=make([][]int,length)
|
||||
for i:=0;i<length;i++{
|
||||
dp[i]=make([]int,2)
|
||||
}
|
||||
|
||||
dp[0][0]=-prices[0]
|
||||
dp[0][1]=0
|
||||
for i:=1;i<length;i++{
|
||||
dp[i][0]=max(dp[i-1][0],-prices[i])
|
||||
dp[i][1]=max(dp[i-1][1],dp[i-1][0]+prices[i])
|
||||
}
|
||||
return dp[length-1][1]
|
||||
}
|
||||
|
||||
func max(a,b int)int {
|
||||
if a>b{
|
||||
return a
|
||||
}
|
||||
return b
|
||||
}
|
||||
```
|
||||
|
||||
|
||||
|
||||
|
||||
@ -1,10 +1,10 @@
|
||||
<p align="center">
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/RsdcQ9umo09R6cfnwXZlrQ"><img src="https://img.shields.io/badge/PDF下载-代码随想录-blueviolet" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw"><img src="https://img.shields.io/badge/刷题-微信群-green" alt=""></a>
|
||||
<a href="https://img-blog.csdnimg.cn/20201210231711160.png"><img src="https://img.shields.io/badge/公众号-代码随想录-brightgreen" alt=""></a>
|
||||
<a href="https://space.bilibili.com/525438321"><img src="https://img.shields.io/badge/B站-代码随想录-orange" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
</p>
|
||||
<p align="center"><strong>欢迎大家参与本项目，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
<p align="center"><strong>欢迎大家<a href="https://mp.weixin.qq.com/s/tqCxrMEU-ajQumL1i8im9A">参与本项目</a>，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
|
||||
|
||||
## 122.买卖股票的最佳时机II
|
||||
@ -133,9 +133,10 @@ public:
|
||||
|
||||
## 其他语言版本
|
||||
|
||||
|
||||
Java：
|
||||
|
||||
```java
|
||||
// 贪心思路
|
||||
class Solution {
|
||||
public int maxProfit(int[] prices) {
|
||||
int sum = 0;
|
||||
@ -153,6 +154,29 @@ class Solution {
|
||||
}
|
||||
```
|
||||
|
||||
```java
|
||||
class Solution { // 动态规划
|
||||
public int maxProfit(int[] prices) {
|
||||
// [天数][是否持有股票]
|
||||
int[][] dp = new int[prices.length][2];
|
||||
|
||||
// bad case
|
||||
dp[0][0] = 0;
|
||||
dp[0][1] = -prices[0];
|
||||
|
||||
for (int i = 1; i < prices.length; i++) {
|
||||
// dp公式
|
||||
dp[i][0] = Math.max(dp[i - 1][0], dp[i - 1][1] + prices[i]);
|
||||
dp[i][1] = Math.max(dp[i - 1][1], dp[i - 1][0] - prices[i]);
|
||||
}
|
||||
|
||||
return dp[prices.length - 1][0];
|
||||
}
|
||||
}
|
||||
```
|
||||
|
||||
|
||||
|
||||
Python：
|
||||
```python
|
||||
class Solution:
|
||||
@ -172,4 +196,4 @@ Go：
|
||||
* 作者微信：[程序员Carl](https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw)
|
||||
* B站视频：[代码随想录](https://space.bilibili.com/525438321)
|
||||
* 知识星球：[代码随想录](https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ)
|
||||
<div align="center"><img src=../pics/公众号.png width=450 alt=> </img></div>
|
||||
<div align="center"><img src=../pics/公众号.png width=450 alt=> </img></div>
|
||||
|
||||
@ -1,10 +1,10 @@
|
||||
<p align="center">
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/RsdcQ9umo09R6cfnwXZlrQ"><img src="https://img.shields.io/badge/PDF下载-代码随想录-blueviolet" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw"><img src="https://img.shields.io/badge/刷题-微信群-green" alt=""></a>
|
||||
<a href="https://img-blog.csdnimg.cn/20201210231711160.png"><img src="https://img.shields.io/badge/公众号-代码随想录-brightgreen" alt=""></a>
|
||||
<a href="https://space.bilibili.com/525438321"><img src="https://img.shields.io/badge/B站-代码随想录-orange" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
</p>
|
||||
<p align="center"><strong>欢迎大家参与本项目，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
<p align="center"><strong>欢迎大家<a href="https://mp.weixin.qq.com/s/tqCxrMEU-ajQumL1i8im9A">参与本项目</a>，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
|
||||
## 122.买卖股票的最佳时机II
|
||||
|
||||
@ -136,24 +136,31 @@ Java：
|
||||
```java
|
||||
// 动态规划
|
||||
class Solution
|
||||
// 实现1：二维数组存储
|
||||
// 可以将每天持有与否的情况分别用 dp[i][0] 和 dp[i][1] 来进行存储
|
||||
// 时间复杂度：O(n)，空间复杂度O(n)
|
||||
public int maxProfit(int[] prices) {
|
||||
int n = prices.length;
|
||||
int[][] dp = new int[n][2];
|
||||
dp[0][0] = 0;
|
||||
int[][] dp = new int[n][2]; // 创建二维数组存储状态
|
||||
dp[0][0] = 0; // 初始状态
|
||||
dp[0][1] = -prices[0];
|
||||
for (int i = 1; i < n; ++i) {
|
||||
dp[i][0] = Math.max(dp[i - 1][0], dp[i - 1][1] + prices[i]);
|
||||
dp[i][1] = Math.max(dp[i - 1][1], dp[i - 1][0] - prices[i]);
|
||||
dp[i][0] = Math.max(dp[i - 1][0], dp[i - 1][1] + prices[i]); // 第 i 天，没有股票
|
||||
dp[i][1] = Math.max(dp[i - 1][1], dp[i - 1][0] - prices[i]); // 第 i 天，持有股票
|
||||
}
|
||||
return dp[n - 1][0];
|
||||
return dp[n - 1][0]; // 卖出股票收益高于持有股票收益，因此取[0]
|
||||
}
|
||||
|
||||
// 实现2：变量存储
|
||||
// 第一种方法需要用二维数组存储，有空间开销，其实关心的仅仅是前一天的状态，不关注更多的历史信息
|
||||
// 因此，可以仅保存前一天的信息存入 dp0、dp1 这 2 个变量即可
|
||||
// 时间复杂度：O(n)，空间复杂度O(1)
|
||||
public int maxProfit(int[] prices) {
|
||||
int n = prices.length;
|
||||
int dp0 = 0, dp1 = -prices[0];
|
||||
int dp0 = 0, dp1 = -prices[0]; // 定义变量，存储初始状态
|
||||
for (int i = 1; i < n; ++i) {
|
||||
int newDp0 = Math.max(dp0, dp1 + prices[i]);
|
||||
int newDp1 = Math.max(dp1, dp0 - prices[i]);
|
||||
int newDp0 = Math.max(dp0, dp1 + prices[i]); // 第 i 天，没有股票
|
||||
int newDp1 = Math.max(dp1, dp0 - prices[i]); // 第 i 天，持有股票
|
||||
dp0 = newDp0;
|
||||
dp1 = newDp1;
|
||||
}
|
||||
|
||||
@ -1,10 +1,10 @@
|
||||
<p align="center">
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/RsdcQ9umo09R6cfnwXZlrQ"><img src="https://img.shields.io/badge/PDF下载-代码随想录-blueviolet" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw"><img src="https://img.shields.io/badge/刷题-微信群-green" alt=""></a>
|
||||
<a href="https://img-blog.csdnimg.cn/20201210231711160.png"><img src="https://img.shields.io/badge/公众号-代码随想录-brightgreen" alt=""></a>
|
||||
<a href="https://space.bilibili.com/525438321"><img src="https://img.shields.io/badge/B站-代码随想录-orange" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
</p>
|
||||
<p align="center"><strong>欢迎大家参与本项目，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
<p align="center"><strong>欢迎大家<a href="https://mp.weixin.qq.com/s/tqCxrMEU-ajQumL1i8im9A">参与本项目</a>，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
|
||||
## 123.买卖股票的最佳时机III
|
||||
|
||||
@ -190,9 +190,42 @@ dp[1] = max(dp[1], dp[0] - prices[i]); 如果dp[1]取dp[1]，即保持买入股
|
||||
|
||||
## 其他语言版本
|
||||
|
||||
|
||||
Java：
|
||||
|
||||
```java
|
||||
class Solution { // 动态规划
|
||||
public int maxProfit(int[] prices) {
|
||||
// 可交易次数
|
||||
int k = 2;
|
||||
|
||||
// [天数][交易次数][是否持有股票]
|
||||
int[][][] dp = new int[prices.length][k + 1][2];
|
||||
|
||||
// badcase
|
||||
dp[0][0][0] = 0;
|
||||
dp[0][0][1] = Integer.MIN_VALUE;
|
||||
dp[0][1][0] = 0;
|
||||
dp[0][1][1] = -prices[0];
|
||||
dp[0][2][0] = 0;
|
||||
dp[0][2][1] = Integer.MIN_VALUE;
|
||||
|
||||
for (int i = 1; i < prices.length; i++) {
|
||||
for (int j = 2; j >= 1; j--) {
|
||||
// dp公式
|
||||
dp[i][j][0] = Math.max(dp[i - 1][j][0], dp[i - 1][j][1] + prices[i]);
|
||||
dp[i][j][1] = Math.max(dp[i - 1][j][1], dp[i - 1][j - 1][0] - prices[i]);
|
||||
}
|
||||
}
|
||||
|
||||
int res = 0;
|
||||
for (int i = 1; i < 3; i++) {
|
||||
res = Math.max(res, dp[prices.length - 1][i][0]);
|
||||
}
|
||||
return res;
|
||||
}
|
||||
}
|
||||
```
|
||||
|
||||
|
||||
Python：
|
||||
|
||||
|
||||
@ -1,10 +1,10 @@
|
||||
<p align="center">
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/RsdcQ9umo09R6cfnwXZlrQ"><img src="https://img.shields.io/badge/PDF下载-代码随想录-blueviolet" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw"><img src="https://img.shields.io/badge/刷题-微信群-green" alt=""></a>
|
||||
<a href="https://img-blog.csdnimg.cn/20201210231711160.png"><img src="https://img.shields.io/badge/公众号-代码随想录-brightgreen" alt=""></a>
|
||||
<a href="https://space.bilibili.com/525438321"><img src="https://img.shields.io/badge/B站-代码随想录-orange" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
</p>
|
||||
<p align="center"><strong>欢迎大家参与本项目，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
<p align="center"><strong>欢迎大家<a href="https://mp.weixin.qq.com/s/tqCxrMEU-ajQumL1i8im9A">参与本项目</a>，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
|
||||
|
||||
> 切割问题其实是一种组合问题！
|
||||
|
||||
@ -1,10 +1,10 @@
|
||||
<p align="center">
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/RsdcQ9umo09R6cfnwXZlrQ"><img src="https://img.shields.io/badge/PDF下载-代码随想录-blueviolet" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw"><img src="https://img.shields.io/badge/刷题-微信群-green" alt=""></a>
|
||||
<a href="https://img-blog.csdnimg.cn/20201210231711160.png"><img src="https://img.shields.io/badge/公众号-代码随想录-brightgreen" alt=""></a>
|
||||
<a href="https://space.bilibili.com/525438321"><img src="https://img.shields.io/badge/B站-代码随想录-orange" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
</p>
|
||||
<p align="center"><strong>欢迎大家参与本项目，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
<p align="center"><strong>欢迎大家<a href="https://mp.weixin.qq.com/s/tqCxrMEU-ajQumL1i8im9A">参与本项目</a>，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
|
||||
|
||||
## 134. 加油站
|
||||
@ -223,7 +223,21 @@ class Solution {
|
||||
```
|
||||
|
||||
Python：
|
||||
|
||||
```python
|
||||
class Solution:
|
||||
def canCompleteCircuit(self, gas: List[int], cost: List[int]) -> int:
|
||||
start = 0
|
||||
curSum = 0
|
||||
totalSum = 0
|
||||
for i in range(len(gas)):
|
||||
curSum += gas[i] - cost[i]
|
||||
totalSum += gas[i] - cost[i]
|
||||
if curSum < 0:
|
||||
curSum = 0
|
||||
start = i + 1
|
||||
if totalSum < 0: return -1
|
||||
return start
|
||||
```
|
||||
|
||||
Go：
|
||||
|
||||
@ -234,4 +248,4 @@ Go：
|
||||
* 作者微信：[程序员Carl](https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw)
|
||||
* B站视频：[代码随想录](https://space.bilibili.com/525438321)
|
||||
* 知识星球：[代码随想录](https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ)
|
||||
<div align="center"><img src=../pics/公众号.png width=450 alt=> </img></div>
|
||||
<div align="center"><img src=../pics/公众号.png width=450 alt=> </img></div>
|
||||
|
||||
@ -1,10 +1,10 @@
|
||||
<p align="center">
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/RsdcQ9umo09R6cfnwXZlrQ"><img src="https://img.shields.io/badge/PDF下载-代码随想录-blueviolet" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw"><img src="https://img.shields.io/badge/刷题-微信群-green" alt=""></a>
|
||||
<a href="https://img-blog.csdnimg.cn/20201210231711160.png"><img src="https://img.shields.io/badge/公众号-代码随想录-brightgreen" alt=""></a>
|
||||
<a href="https://space.bilibili.com/525438321"><img src="https://img.shields.io/badge/B站-代码随想录-orange" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
</p>
|
||||
<p align="center"><strong>欢迎大家参与本项目，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
<p align="center"><strong>欢迎大家<a href="https://mp.weixin.qq.com/s/tqCxrMEU-ajQumL1i8im9A">参与本项目</a>，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
|
||||
|
||||
## 135. 分发糖果
|
||||
@ -161,7 +161,18 @@ class Solution {
|
||||
```
|
||||
|
||||
Python：
|
||||
|
||||
```python
|
||||
class Solution:
|
||||
def candy(self, ratings: List[int]) -> int:
|
||||
candyVec = [1] * len(ratings)
|
||||
for i in range(1, len(ratings)):
|
||||
if ratings[i] > ratings[i - 1]:
|
||||
candyVec[i] = candyVec[i - 1] + 1
|
||||
for j in range(len(ratings) - 2, -1, -1):
|
||||
if ratings[j] > ratings[j + 1]:
|
||||
candyVec[j] = max(candyVec[j], candyVec[j + 1] + 1)
|
||||
return sum(candyVec)
|
||||
```
|
||||
|
||||
Go：
|
||||
|
||||
@ -172,4 +183,4 @@ Go：
|
||||
* 作者微信：[程序员Carl](https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw)
|
||||
* B站视频：[代码随想录](https://space.bilibili.com/525438321)
|
||||
* 知识星球：[代码随想录](https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ)
|
||||
<div align="center"><img src=../pics/公众号.png width=450 alt=> </img></div>
|
||||
<div align="center"><img src=../pics/公众号.png width=450 alt=> </img></div>
|
||||
|
||||
@ -1,10 +1,10 @@
|
||||
<p align="center">
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/RsdcQ9umo09R6cfnwXZlrQ"><img src="https://img.shields.io/badge/PDF下载-代码随想录-blueviolet" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw"><img src="https://img.shields.io/badge/刷题-微信群-green" alt=""></a>
|
||||
<a href="https://img-blog.csdnimg.cn/20201210231711160.png"><img src="https://img.shields.io/badge/公众号-代码随想录-brightgreen" alt=""></a>
|
||||
<a href="https://space.bilibili.com/525438321"><img src="https://img.shields.io/badge/B站-代码随想录-orange" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
</p>
|
||||
<p align="center"><strong>欢迎大家参与本项目，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
<p align="center"><strong>欢迎大家<a href="https://mp.weixin.qq.com/s/tqCxrMEU-ajQumL1i8im9A">参与本项目</a>，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
# 动态规划：单词拆分
|
||||
|
||||
## 139.单词拆分
|
||||
@ -254,7 +254,25 @@ Python：
|
||||
|
||||
|
||||
Go：
|
||||
|
||||
```Go
|
||||
func wordBreak(s string,wordDict []string) bool {
|
||||
wordDictSet:=make(map[string]bool)
|
||||
for _,w:=range wordDict{
|
||||
wordDictSet[w]=true
|
||||
}
|
||||
dp:=make([]bool,len(s)+1)
|
||||
dp[0]=true
|
||||
for i:=1;i<=len(s);i++{
|
||||
for j:=0;j<i;j++{
|
||||
if dp[j]&& wordDictSet[s[j:i]]{
|
||||
dp[i]=true
|
||||
break
|
||||
}
|
||||
}
|
||||
}
|
||||
return dp[len(s)]
|
||||
}
|
||||
```
|
||||
|
||||
|
||||
|
||||
@ -262,4 +280,4 @@ Go：
|
||||
* 作者微信：[程序员Carl](https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw)
|
||||
* B站视频：[代码随想录](https://space.bilibili.com/525438321)
|
||||
* 知识星球：[代码随想录](https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ)
|
||||
<div align="center"><img src=../pics/公众号.png width=450 alt=> </img></div>
|
||||
<div align="center"><img src=../pics/公众号.png width=450 alt=> </img></div>
|
||||
|
||||
@ -1,10 +1,10 @@
|
||||
<p align="center">
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/RsdcQ9umo09R6cfnwXZlrQ"><img src="https://img.shields.io/badge/PDF下载-代码随想录-blueviolet" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw"><img src="https://img.shields.io/badge/刷题-微信群-green" alt=""></a>
|
||||
<a href="https://img-blog.csdnimg.cn/20201210231711160.png"><img src="https://img.shields.io/badge/公众号-代码随想录-brightgreen" alt=""></a>
|
||||
<a href="https://space.bilibili.com/525438321"><img src="https://img.shields.io/badge/B站-代码随想录-orange" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
</p>
|
||||
<p align="center"><strong>欢迎大家参与本项目，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
<p align="center"><strong>欢迎大家<a href="https://mp.weixin.qq.com/s/tqCxrMEU-ajQumL1i8im9A">参与本项目</a>，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
|
||||
|
||||
|
||||
@ -234,6 +234,73 @@ class Solution:
|
||||
```
|
||||
|
||||
Go：
|
||||
```func detectCycle(head *ListNode) *ListNode {
|
||||
if head ==nil{
|
||||
return head
|
||||
}
|
||||
slow:=head
|
||||
fast:=head.Next
|
||||
|
||||
for fast!=nil&&fast.Next!=nil{
|
||||
if fast==slow{
|
||||
slow=head
|
||||
fast=fast.Next
|
||||
for fast!=slow {
|
||||
fast=fast.Next
|
||||
slow=slow.Next
|
||||
}
|
||||
return slow
|
||||
}
|
||||
fast=fast.Next.Next
|
||||
slow=slow.Next
|
||||
}
|
||||
return nil
|
||||
}
|
||||
```
|
||||
|
||||
javaScript
|
||||
|
||||
```js
|
||||
// 两种循环实现方式
|
||||
/**
|
||||
* @param {ListNode} head
|
||||
* @return {ListNode}
|
||||
*/
|
||||
// 先判断是否是环形链表
|
||||
var detectCycle = function(head) {
|
||||
if(!head || !head.next) return null;
|
||||
let slow =head.next, fast = head.next.next;
|
||||
while(fast && fast.next && fast!== slow) {
|
||||
slow = slow.next;
|
||||
fast = fast.next.next;
|
||||
}
|
||||
if(!fast || !fast.next ) return null;
|
||||
slow = head;
|
||||
while (fast !== slow) {
|
||||
slow = slow.next;
|
||||
fast = fast.next;
|
||||
}
|
||||
return slow;
|
||||
};
|
||||
|
||||
var detectCycle = function(head) {
|
||||
if(!head || !head.next) return null;
|
||||
let slow =head.next, fast = head.next.next;
|
||||
while(fast && fast.next) {
|
||||
slow = slow.next;
|
||||
fast = fast.next.next;
|
||||
if(fast == slow) {
|
||||
slow = head;
|
||||
while (fast !== slow) {
|
||||
slow = slow.next;
|
||||
fast = fast.next;
|
||||
}
|
||||
return slow;
|
||||
}
|
||||
}
|
||||
return null;
|
||||
};
|
||||
```
|
||||
|
||||
|
||||
-----------------------
|
||||
|
||||
@ -1,10 +1,10 @@
|
||||
<p align="center">
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/RsdcQ9umo09R6cfnwXZlrQ"><img src="https://img.shields.io/badge/PDF下载-代码随想录-blueviolet" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw"><img src="https://img.shields.io/badge/刷题-微信群-green" alt=""></a>
|
||||
<a href="https://img-blog.csdnimg.cn/20201210231711160.png"><img src="https://img.shields.io/badge/公众号-代码随想录-brightgreen" alt=""></a>
|
||||
<a href="https://space.bilibili.com/525438321"><img src="https://img.shields.io/badge/B站-代码随想录-orange" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
</p>
|
||||
<p align="center"><strong>欢迎大家参与本项目，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
<p align="center"><strong>欢迎大家<a href="https://mp.weixin.qq.com/s/tqCxrMEU-ajQumL1i8im9A">参与本项目</a>，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
|
||||
|
||||
|
||||
|
||||
@ -1,10 +1,10 @@
|
||||
<p align="center">
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/RsdcQ9umo09R6cfnwXZlrQ"><img src="https://img.shields.io/badge/PDF下载-代码随想录-blueviolet" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw"><img src="https://img.shields.io/badge/刷题-微信群-green" alt=""></a>
|
||||
<a href="https://img-blog.csdnimg.cn/20201210231711160.png"><img src="https://img.shields.io/badge/公众号-代码随想录-brightgreen" alt=""></a>
|
||||
<a href="https://space.bilibili.com/525438321"><img src="https://img.shields.io/badge/B站-代码随想录-orange" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
</p>
|
||||
<p align="center"><strong>欢迎大家参与本项目，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
<p align="center"><strong>欢迎大家<a href="https://mp.weixin.qq.com/s/tqCxrMEU-ajQumL1i8im9A">参与本项目</a>，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
|
||||
|
||||
|
||||
@ -183,7 +183,7 @@ public:
|
||||
int end = 0; // 反转的单词在字符串里终止位置
|
||||
bool entry = false; // 标记枚举字符串的过程中是否已经进入了单词区间
|
||||
for (int i = 0; i < s.size(); i++) { // 开始反转单词
|
||||
if ((!entry) || (s[i] != ' ' && s[i - 1] == ' ')) {
|
||||
if ((!entry))) {
|
||||
start = i; // 确定单词起始位置
|
||||
entry = true; // 进入单词区间
|
||||
}
|
||||
|
||||
@ -1,10 +1,10 @@
|
||||
<p align="center">
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/RsdcQ9umo09R6cfnwXZlrQ"><img src="https://img.shields.io/badge/PDF下载-代码随想录-blueviolet" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw"><img src="https://img.shields.io/badge/刷题-微信群-green" alt=""></a>
|
||||
<a href="https://img-blog.csdnimg.cn/20201210231711160.png"><img src="https://img.shields.io/badge/公众号-代码随想录-brightgreen" alt=""></a>
|
||||
<a href="https://space.bilibili.com/525438321"><img src="https://img.shields.io/badge/B站-代码随想录-orange" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
</p>
|
||||
<p align="center"><strong>欢迎大家参与本项目，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
<p align="center"><strong>欢迎大家<a href="https://mp.weixin.qq.com/s/tqCxrMEU-ajQumL1i8im9A">参与本项目</a>，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
|
||||
## 188.买卖股票的最佳时机IV
|
||||
|
||||
@ -25,7 +25,7 @@
|
||||
输入：k = 2, prices = [3,2,6,5,0,3]
|
||||
输出：7
|
||||
解释：在第 2 天 (股票价格 = 2) 的时候买入，在第 3 天 (股票价格 = 6) 的时候卖出, 这笔交易所能获得利润 = 6-2 = 4。随后，在第 5 天 (股票价格 = 0) 的时候买入，在第 6 天 (股票价格 = 3) 的时候卖出, 这笔交易所能获得利润 = 3-0 = 3 。
|
||||
|
||||
|
||||
|
||||
提示：
|
||||
|
||||
@ -167,9 +167,48 @@ public:
|
||||
|
||||
## 其他语言版本
|
||||
|
||||
|
||||
Java：
|
||||
|
||||
```java
|
||||
class Solution { //动态规划
|
||||
public int maxProfit(int k, int[] prices) {
|
||||
if (prices == null || prices.length < 2 || k == 0) {
|
||||
return 0;
|
||||
}
|
||||
|
||||
// [天数][交易次数][是否持有股票]
|
||||
int[][][] dp = new int[prices.length][k + 1][2];
|
||||
|
||||
// bad case
|
||||
dp[0][0][0] = 0;
|
||||
dp[0][0][1] = Integer.MIN_VALUE;
|
||||
dp[0][1][0] = 0;
|
||||
dp[0][1][1] = -prices[0];
|
||||
// dp[0][j][0] 都均为0
|
||||
// dp[0][j][1] 异常值都取Integer.MIN_VALUE;
|
||||
for (int i = 2; i < k + 1; i++) {
|
||||
dp[0][i][0] = 0;
|
||||
dp[0][i][1] = Integer.MIN_VALUE;
|
||||
}
|
||||
|
||||
for (int i = 1; i < prices.length; i++) {
|
||||
for (int j = k; j >= 1; j--) {
|
||||
// dp公式
|
||||
dp[i][j][0] = Math.max(dp[i - 1][j][0], dp[i - 1][j][1] + prices[i]);
|
||||
dp[i][j][1] = Math.max(dp[i - 1][j][1], dp[i - 1][j - 1][0] - prices[i]);
|
||||
}
|
||||
}
|
||||
|
||||
int res = 0;
|
||||
for (int i = 1; i < k + 1; i++) {
|
||||
res = Math.max(res, dp[prices.length - 1][i][0]);
|
||||
}
|
||||
|
||||
return res;
|
||||
}
|
||||
}
|
||||
```
|
||||
|
||||
|
||||
Python：
|
||||
|
||||
|
||||
@ -1,10 +1,10 @@
|
||||
<p align="center">
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/RsdcQ9umo09R6cfnwXZlrQ"><img src="https://img.shields.io/badge/PDF下载-代码随想录-blueviolet" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw"><img src="https://img.shields.io/badge/刷题-微信群-green" alt=""></a>
|
||||
<a href="https://img-blog.csdnimg.cn/20201210231711160.png"><img src="https://img.shields.io/badge/公众号-代码随想录-brightgreen" alt=""></a>
|
||||
<a href="https://space.bilibili.com/525438321"><img src="https://img.shields.io/badge/B站-代码随想录-orange" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
</p>
|
||||
<p align="center"><strong>欢迎大家参与本项目，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
<p align="center"><strong>欢迎大家<a href="https://mp.weixin.qq.com/s/tqCxrMEU-ajQumL1i8im9A">参与本项目</a>，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
|
||||
## 198.打家劫舍
|
||||
|
||||
|
||||
@ -1,10 +1,10 @@
|
||||
<p align="center">
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/RsdcQ9umo09R6cfnwXZlrQ"><img src="https://img.shields.io/badge/PDF下载-代码随想录-blueviolet" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw"><img src="https://img.shields.io/badge/刷题-微信群-green" alt=""></a>
|
||||
<a href="https://img-blog.csdnimg.cn/20201210231711160.png"><img src="https://img.shields.io/badge/公众号-代码随想录-brightgreen" alt=""></a>
|
||||
<a href="https://space.bilibili.com/525438321"><img src="https://img.shields.io/badge/B站-代码随想录-orange" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
</p>
|
||||
<p align="center"><strong>欢迎大家参与本项目，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
<p align="center"><strong>欢迎大家<a href="https://mp.weixin.qq.com/s/tqCxrMEU-ajQumL1i8im9A">参与本项目</a>，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
|
||||
|
||||
|
||||
@ -112,6 +112,40 @@ Python：
|
||||
|
||||
Go：
|
||||
|
||||
javaScript:
|
||||
|
||||
```js
|
||||
function getN(n) {
|
||||
if (n == 1 || n == 0) return n;
|
||||
let res = 0;
|
||||
while (n) {
|
||||
res += (n % 10) * (n % 10);
|
||||
n = parseInt(n / 10);
|
||||
}
|
||||
return res;
|
||||
}
|
||||
|
||||
var isHappy = function(n) {
|
||||
const sumSet = new Set();
|
||||
while (n != 1 && !sumSet.has(n)) {
|
||||
sumSet.add(n);
|
||||
n = getN(n);
|
||||
}
|
||||
return n == 1;
|
||||
};
|
||||
|
||||
// 使用环形链表的思想 说明出现闭环 退出循环
|
||||
var isHappy = function(n) {
|
||||
if (getN(n) == 1) return true;
|
||||
let a = getN(n), b = getN(getN(n));
|
||||
// 如果 a === b
|
||||
while (b !== 1 && getN(b) !== 1 && a !== b) {
|
||||
a = getN(a);
|
||||
b = getN(getN(b));
|
||||
}
|
||||
return b === 1 || getN(b) === 1 ;
|
||||
};
|
||||
```
|
||||
|
||||
|
||||
|
||||
|
||||
@ -1,10 +1,10 @@
|
||||
<p align="center">
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/RsdcQ9umo09R6cfnwXZlrQ"><img src="https://img.shields.io/badge/PDF下载-代码随想录-blueviolet" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw"><img src="https://img.shields.io/badge/刷题-微信群-green" alt=""></a>
|
||||
<a href="https://img-blog.csdnimg.cn/20201210231711160.png"><img src="https://img.shields.io/badge/公众号-代码随想录-brightgreen" alt=""></a>
|
||||
<a href="https://space.bilibili.com/525438321"><img src="https://img.shields.io/badge/B站-代码随想录-orange" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
</p>
|
||||
<p align="center"><strong>欢迎大家参与本项目，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
<p align="center"><strong>欢迎大家<a href="https://mp.weixin.qq.com/s/tqCxrMEU-ajQumL1i8im9A">参与本项目</a>，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
|
||||
|
||||
> 链表操作中，可以使用原链表来直接进行删除操作，也可以设置一个虚拟头结点在进行删除操作，接下来看一看哪种方式更方便。
|
||||
@ -201,6 +201,28 @@ Python：
|
||||
|
||||
Go：
|
||||
|
||||
javaScript:
|
||||
|
||||
```js
|
||||
/**
|
||||
* @param {ListNode} head
|
||||
* @param {number} val
|
||||
* @return {ListNode}
|
||||
*/
|
||||
var removeElements = function(head, val) {
|
||||
const ret = new ListNode(0, head);
|
||||
let cur = ret;
|
||||
while(cur.next) {
|
||||
if(cur.next.val === val) {
|
||||
cur.next = cur.next.next;
|
||||
continue;
|
||||
}
|
||||
cur = cur.next;
|
||||
}
|
||||
return ret.next;
|
||||
};
|
||||
```
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
@ -1,10 +1,10 @@
|
||||
<p align="center">
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/RsdcQ9umo09R6cfnwXZlrQ"><img src="https://img.shields.io/badge/PDF下载-代码随想录-blueviolet" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw"><img src="https://img.shields.io/badge/刷题-微信群-green" alt=""></a>
|
||||
<a href="https://img-blog.csdnimg.cn/20201210231711160.png"><img src="https://img.shields.io/badge/公众号-代码随想录-brightgreen" alt=""></a>
|
||||
<a href="https://space.bilibili.com/525438321"><img src="https://img.shields.io/badge/B站-代码随想录-orange" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
</p>
|
||||
<p align="center"><strong>欢迎大家参与本项目，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
<p align="center"><strong>欢迎大家<a href="https://mp.weixin.qq.com/s/tqCxrMEU-ajQumL1i8im9A">参与本项目</a>，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
|
||||
|
||||
> 反转链表的写法很简单，一些同学甚至可以背下来但过一阵就忘了该咋写，主要是因为没有理解真正的反转过程。
|
||||
@ -147,6 +147,90 @@ Python：
|
||||
|
||||
Go：
|
||||
|
||||
```go
|
||||
//双指针
|
||||
func reverseList(head *ListNode) *ListNode {
|
||||
var pre *ListNode
|
||||
cur := head
|
||||
for cur != nil {
|
||||
next := cur.Next
|
||||
cur.Next = pre
|
||||
pre = cur
|
||||
cur = next
|
||||
}
|
||||
return pre
|
||||
}
|
||||
|
||||
//递归
|
||||
func reverseList(head *ListNode) *ListNode {
|
||||
return help(nil, head)
|
||||
}
|
||||
|
||||
func help(pre, head *ListNode)*ListNode{
|
||||
if head == nil {
|
||||
return pre
|
||||
}
|
||||
next := head.Next
|
||||
head.Next = pre
|
||||
return help(head, next)
|
||||
}
|
||||
|
||||
```
|
||||
javaScript:
|
||||
|
||||
```js
|
||||
/**
|
||||
* @param {ListNode} head
|
||||
* @return {ListNode}
|
||||
*/
|
||||
|
||||
// 双指针：
|
||||
var reverseList = function(head) {
|
||||
if(!head || !head.next) return head;
|
||||
let temp = null, pre = null, cur = head;
|
||||
while(cur) {
|
||||
temp = cur.next;
|
||||
cur.next = pre;
|
||||
pre = cur;
|
||||
cur = temp;
|
||||
}
|
||||
// temp = cur = null;
|
||||
return pre;
|
||||
};
|
||||
|
||||
// 递归：
|
||||
var reverse = function(pre, head) {
|
||||
if(!head) return pre;
|
||||
const temp = head.next;
|
||||
head.next = pre;
|
||||
pre = head
|
||||
return reverse(pre, temp);
|
||||
}
|
||||
|
||||
var reverseList = function(head) {
|
||||
return reverse(null, head);
|
||||
};
|
||||
|
||||
// 递归2
|
||||
var reverse = function(head) {
|
||||
if(!head || !head.next) return head;
|
||||
// 从后往前翻
|
||||
const pre = reverse(head.next);
|
||||
head.next = pre.next;
|
||||
pre.next = head;
|
||||
return head;
|
||||
}
|
||||
|
||||
var reverseList = function(head) {
|
||||
let cur = head;
|
||||
while(cur && cur.next) {
|
||||
cur = cur.next;
|
||||
}
|
||||
reverse(head);
|
||||
return cur;
|
||||
};
|
||||
```
|
||||
|
||||
|
||||
|
||||
|
||||
@ -154,4 +238,4 @@ Go：
|
||||
* 作者微信：[程序员Carl](https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw)
|
||||
* B站视频：[代码随想录](https://space.bilibili.com/525438321)
|
||||
* 知识星球：[代码随想录](https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ)
|
||||
<div align="center"><img src=../pics/公众号.png width=450 alt=> </img></div>
|
||||
<div align="center"><img src=../pics/公众号.png width=450 alt=> </img></div>
|
||||
|
||||
@ -1,10 +1,10 @@
|
||||
<p align="center">
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/RsdcQ9umo09R6cfnwXZlrQ"><img src="https://img.shields.io/badge/PDF下载-代码随想录-blueviolet" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw"><img src="https://img.shields.io/badge/刷题-微信群-green" alt=""></a>
|
||||
<a href="https://img-blog.csdnimg.cn/20201210231711160.png"><img src="https://img.shields.io/badge/公众号-代码随想录-brightgreen" alt=""></a>
|
||||
<a href="https://space.bilibili.com/525438321"><img src="https://img.shields.io/badge/B站-代码随想录-orange" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
</p>
|
||||
<p align="center"><strong>欢迎大家参与本项目，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
<p align="center"><strong>欢迎大家<a href="https://mp.weixin.qq.com/s/tqCxrMEU-ajQumL1i8im9A">参与本项目</a>，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
|
||||
|
||||
## 209.长度最小的子数组
|
||||
@ -172,22 +172,51 @@ Python：
|
||||
|
||||
|
||||
Go：
|
||||
```go
|
||||
func minSubArrayLen(target int, nums []int) int {
|
||||
i := 0
|
||||
l := len(nums) // 数组长度
|
||||
sum := 0 // 子数组之和
|
||||
result := l + 1 // 初始化返回长度为l+1，目的是为了判断“不存在符合条件的子数组，返回0”的情况
|
||||
for j := 0; j < l; j++ {
|
||||
sum += nums[j]
|
||||
for sum >= target {
|
||||
subLength := j - i + 1
|
||||
if subLength < result {
|
||||
result = subLength
|
||||
}
|
||||
sum -= nums[i]
|
||||
i++
|
||||
}
|
||||
}
|
||||
if result == l+1 {
|
||||
return 0
|
||||
} else {
|
||||
return result
|
||||
}
|
||||
}
|
||||
```
|
||||
|
||||
|
||||
JavaScript:
|
||||
```
|
||||
var minSubArrayLen = (target, nums) => {
|
||||
let left = 0, right = 0,win = Infinity,sum = 0;
|
||||
while(right < nums.length){
|
||||
sum += nums[right];
|
||||
while(sum >= target){
|
||||
win = right - left + 1 < win? right - left + 1 : win;
|
||||
sum -= nums[left];
|
||||
left++;
|
||||
}
|
||||
right++;
|
||||
|
||||
```js
|
||||
|
||||
var minSubArrayLen = function(target, nums) {
|
||||
// 长度计算一次
|
||||
const len = nums.length;
|
||||
let l = r = sum = 0,
|
||||
res = len + 1; // 子数组最大不会超过自身
|
||||
while(r < len) {
|
||||
sum += nums[r++];
|
||||
// 窗口滑动
|
||||
while(sum >= target) {
|
||||
// r始终为开区间 [l, r)
|
||||
res = res < r - l ? res : r - l;
|
||||
sum-=nums[l++];
|
||||
}
|
||||
}
|
||||
return win === Infinity? 0:win;
|
||||
return res > len ? 0 : res;
|
||||
};
|
||||
```
|
||||
|
||||
@ -195,4 +224,4 @@ var minSubArrayLen = (target, nums) => {
|
||||
* 作者微信：[程序员Carl](https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw)
|
||||
* B站视频：[代码随想录](https://space.bilibili.com/525438321)
|
||||
* 知识星球：[代码随想录](https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ)
|
||||
<div align="center"><img src=../pics/公众号.png width=450 alt=> </img></div>
|
||||
<div align="center"><img src=../pics/公众号.png width=450 alt=> </img></div>
|
||||
|
||||
@ -1,10 +1,10 @@
|
||||
<p align="center">
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/RsdcQ9umo09R6cfnwXZlrQ"><img src="https://img.shields.io/badge/PDF下载-代码随想录-blueviolet" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw"><img src="https://img.shields.io/badge/刷题-微信群-green" alt=""></a>
|
||||
<a href="https://img-blog.csdnimg.cn/20201210231711160.png"><img src="https://img.shields.io/badge/公众号-代码随想录-brightgreen" alt=""></a>
|
||||
<a href="https://space.bilibili.com/525438321"><img src="https://img.shields.io/badge/B站-代码随想录-orange" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
</p>
|
||||
<p align="center"><strong>欢迎大家参与本项目，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
<p align="center"><strong>欢迎大家<a href="https://mp.weixin.qq.com/s/tqCxrMEU-ajQumL1i8im9A">参与本项目</a>，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
|
||||
## 213.打家劫舍II
|
||||
|
||||
@ -122,8 +122,49 @@ class Solution {
|
||||
```
|
||||
|
||||
Python：
|
||||
```Python
|
||||
class Solution:
|
||||
def rob(self, nums: List[int]) -> int:
|
||||
if (n := len(nums)) == 0:
|
||||
return 0
|
||||
if n == 1:
|
||||
return nums[0]
|
||||
result1 = self.robRange(nums, 0, n - 2)
|
||||
result2 = self.robRange(nums, 1, n - 1)
|
||||
return max(result1 , result2)
|
||||
|
||||
def robRange(self, nums: List[int], start: int, end: int) -> int:
|
||||
if end == start: return nums[start]
|
||||
dp = [0] * len(nums)
|
||||
dp[start] = nums[start]
|
||||
dp[start + 1] = max(nums[start], nums[start + 1])
|
||||
for i in range(start + 2, end + 1):
|
||||
dp[i] = max(dp[i -2] + nums[i], dp[i - 1])
|
||||
return dp[end]
|
||||
```
|
||||
|
||||
javascipt:
|
||||
```javascript
|
||||
var rob = function(nums) {
|
||||
const n = nums.length
|
||||
if (n === 0) return 0
|
||||
if (n === 1) return nums[0]
|
||||
const result1 = robRange(nums, 0, n - 2)
|
||||
const result2 = robRange(nums, 1, n - 1)
|
||||
return Math.max(result1, result2)
|
||||
};
|
||||
|
||||
const robRange = (nums, start, end) => {
|
||||
if (end === start) return nums[start]
|
||||
const dp = Array(nums.length).fill(0)
|
||||
dp[start] = nums[start]
|
||||
dp[start + 1] = Math.max(nums[start], nums[start + 1])
|
||||
for (let i = start + 2; i <= end; i++) {
|
||||
dp[i] = Math.max(dp[i - 2] + nums[i], dp[i - 1])
|
||||
}
|
||||
return dp[end]
|
||||
}
|
||||
```
|
||||
Go：
|
||||
|
||||
|
||||
|
||||
@ -1,10 +1,10 @@
|
||||
<p align="center">
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/RsdcQ9umo09R6cfnwXZlrQ"><img src="https://img.shields.io/badge/PDF下载-代码随想录-blueviolet" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw"><img src="https://img.shields.io/badge/刷题-微信群-green" alt=""></a>
|
||||
<a href="https://img-blog.csdnimg.cn/20201210231711160.png"><img src="https://img.shields.io/badge/公众号-代码随想录-brightgreen" alt=""></a>
|
||||
<a href="https://space.bilibili.com/525438321"><img src="https://img.shields.io/badge/B站-代码随想录-orange" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
</p>
|
||||
<p align="center"><strong>欢迎大家参与本项目，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
<p align="center"><strong>欢迎大家<a href="https://mp.weixin.qq.com/s/tqCxrMEU-ajQumL1i8im9A">参与本项目</a>，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
|
||||
|
||||
|
||||
@ -94,7 +94,7 @@ void backtracking(int targetSum, int k, int sum, int startIndex)
|
||||
|
||||
所以 终止代码如下：
|
||||
|
||||
```
|
||||
```C++
|
||||
if (path.size() == k) {
|
||||
if (sum == targetSum) result.push_back(path);
|
||||
return; // 如果path.size() == k 但sum != targetSum 直接返回
|
||||
@ -112,7 +112,7 @@ if (path.size() == k) {
|
||||
|
||||
代码如下：
|
||||
|
||||
```
|
||||
```C++
|
||||
for (int i = startIndex; i <= 9; i++) {
|
||||
sum += i;
|
||||
path.push_back(i);
|
||||
@ -126,7 +126,7 @@ for (int i = startIndex; i <= 9; i++) {
|
||||
|
||||
参照[关于回溯算法，你该了解这些！](https://mp.weixin.qq.com/s/gjSgJbNbd1eAA5WkA-HeWw)中的模板，不难写出如下C++代码：
|
||||
|
||||
```
|
||||
```C++
|
||||
class Solution {
|
||||
private:
|
||||
vector<vector<int>> result; // 存放结果集
|
||||
@ -273,4 +273,4 @@ Go：
|
||||
* 作者微信：[程序员Carl](https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw)
|
||||
* B站视频：[代码随想录](https://space.bilibili.com/525438321)
|
||||
* 知识星球：[代码随想录](https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ)
|
||||
<div align="center"><img src=../pics/公众号.png width=450 alt=> </img></div>
|
||||
<div align="center"><img src=../pics/公众号.png width=450 alt=> </img></div>
|
||||
|
||||
@ -1,10 +1,10 @@
|
||||
<p align="center">
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/RsdcQ9umo09R6cfnwXZlrQ"><img src="https://img.shields.io/badge/PDF下载-代码随想录-blueviolet" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw"><img src="https://img.shields.io/badge/刷题-微信群-green" alt=""></a>
|
||||
<a href="https://img-blog.csdnimg.cn/20201210231711160.png"><img src="https://img.shields.io/badge/公众号-代码随想录-brightgreen" alt=""></a>
|
||||
<a href="https://space.bilibili.com/525438321"><img src="https://img.shields.io/badge/B站-代码随想录-orange" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
</p>
|
||||
<p align="center"><strong>欢迎大家参与本项目，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
<p align="center"><strong>欢迎大家<a href="https://mp.weixin.qq.com/s/tqCxrMEU-ajQumL1i8im9A">参与本项目</a>，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
|
||||
|
||||
## 222.完全二叉树的节点个数
|
||||
@ -250,4 +250,4 @@ Go：
|
||||
* 作者微信：[程序员Carl](https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw)
|
||||
* B站视频：[代码随想录](https://space.bilibili.com/525438321)
|
||||
* 知识星球：[代码随想录](https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ)
|
||||
<div align="center"><img src=../pics/公众号.png width=450 alt=> </img></div>
|
||||
<div align="center"><img src=../pics/公众号.png width=450 alt=> </img></div>
|
||||
|
||||
@ -1,10 +1,10 @@
|
||||
<p align="center">
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/RsdcQ9umo09R6cfnwXZlrQ"><img src="https://img.shields.io/badge/PDF下载-代码随想录-blueviolet" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw"><img src="https://img.shields.io/badge/刷题-微信群-green" alt=""></a>
|
||||
<a href="https://img-blog.csdnimg.cn/20201210231711160.png"><img src="https://img.shields.io/badge/公众号-代码随想录-brightgreen" alt=""></a>
|
||||
<a href="https://space.bilibili.com/525438321"><img src="https://img.shields.io/badge/B站-代码随想录-orange" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
</p>
|
||||
<p align="center"><strong>欢迎大家参与本项目，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
<p align="center"><strong>欢迎大家<a href="https://mp.weixin.qq.com/s/tqCxrMEU-ajQumL1i8im9A">参与本项目</a>，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
|
||||
|
||||
|
||||
@ -156,6 +156,7 @@ public:
|
||||
|
||||
Java：
|
||||
|
||||
使用两个 Queue 实现
|
||||
```java
|
||||
class MyStack {
|
||||
|
||||
@ -205,7 +206,94 @@ class MyStack {
|
||||
* boolean param_4 = obj.empty();
|
||||
*/
|
||||
```
|
||||
使用两个 Deque 实现
|
||||
```java
|
||||
class MyStack {
|
||||
// Deque 接口继承了 Queue 接口
|
||||
// 所以 Queue 中的 add、poll、peek等效于 Deque 中的 addLast、pollFirst、peekFirst
|
||||
Deque<Integer> que1; // 和栈中保持一样元素的队列
|
||||
Deque<Integer> que2; // 辅助队列
|
||||
/** Initialize your data structure here. */
|
||||
public MyStack() {
|
||||
que1 = new ArrayDeque<>();
|
||||
que2 = new ArrayDeque<>();
|
||||
}
|
||||
|
||||
/** Push element x onto stack. */
|
||||
public void push(int x) {
|
||||
que1.addLast(x);
|
||||
}
|
||||
|
||||
/** Removes the element on top of the stack and returns that element. */
|
||||
public int pop() {
|
||||
int size = que1.size();
|
||||
size--;
|
||||
// 将 que1 导入 que2 ，但留下最后一个值
|
||||
while (size-- > 0) {
|
||||
que2.addLast(que1.peekFirst());
|
||||
que1.pollFirst();
|
||||
}
|
||||
|
||||
int res = que1.pollFirst();
|
||||
// 将 que2 对象的引用赋给了 que1 ，此时 que1，que2 指向同一个队列
|
||||
que1 = que2;
|
||||
// 如果直接操作 que2，que1 也会受到影响，所以为 que2 分配一个新的空间
|
||||
que2 = new ArrayDeque<>();
|
||||
return res;
|
||||
}
|
||||
|
||||
/** Get the top element. */
|
||||
public int top() {
|
||||
return que1.peekLast();
|
||||
}
|
||||
|
||||
/** Returns whether the stack is empty. */
|
||||
public boolean empty() {
|
||||
return que1.isEmpty();
|
||||
}
|
||||
}
|
||||
```
|
||||
优化，使用一个 Deque 实现
|
||||
```java
|
||||
class MyStack {
|
||||
// Deque 接口继承了 Queue 接口
|
||||
// 所以 Queue 中的 add、poll、peek等效于 Deque 中的 addLast、pollFirst、peekFirst
|
||||
Deque<Integer> que1;
|
||||
/** Initialize your data structure here. */
|
||||
public MyStack() {
|
||||
que1 = new ArrayDeque<>();
|
||||
}
|
||||
|
||||
/** Push element x onto stack. */
|
||||
public void push(int x) {
|
||||
que1.addLast(x);
|
||||
}
|
||||
|
||||
/** Removes the element on top of the stack and returns that element. */
|
||||
public int pop() {
|
||||
int size = que1.size();
|
||||
size--;
|
||||
// 将 que1 导入 que2 ，但留下最后一个值
|
||||
while (size-- > 0) {
|
||||
que1.addLast(que1.peekFirst());
|
||||
que1.pollFirst();
|
||||
}
|
||||
|
||||
int res = que1.pollFirst();
|
||||
return res;
|
||||
}
|
||||
|
||||
/** Get the top element. */
|
||||
public int top() {
|
||||
return que1.peekLast();
|
||||
}
|
||||
|
||||
/** Returns whether the stack is empty. */
|
||||
public boolean empty() {
|
||||
return que1.isEmpty();
|
||||
}
|
||||
}
|
||||
```
|
||||
|
||||
Python：
|
||||
|
||||
@ -276,4 +364,4 @@ Go：
|
||||
* 作者微信：[程序员Carl](https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw)
|
||||
* B站视频：[代码随想录](https://space.bilibili.com/525438321)
|
||||
* 知识星球：[代码随想录](https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ)
|
||||
<div align="center"><img src=../pics/公众号.png width=450 alt=> </img></div>
|
||||
<div align="center"><img src=../pics/公众号.png width=450 alt=> </img></div>
|
||||
|
||||
@ -1,10 +1,10 @@
|
||||
<p align="center">
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/RsdcQ9umo09R6cfnwXZlrQ"><img src="https://img.shields.io/badge/PDF下载-代码随想录-blueviolet" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw"><img src="https://img.shields.io/badge/刷题-微信群-green" alt=""></a>
|
||||
<a href="https://img-blog.csdnimg.cn/20201210231711160.png"><img src="https://img.shields.io/badge/公众号-代码随想录-brightgreen" alt=""></a>
|
||||
<a href="https://space.bilibili.com/525438321"><img src="https://img.shields.io/badge/B站-代码随想录-orange" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
</p>
|
||||
<p align="center"><strong>欢迎大家参与本项目，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
<p align="center"><strong>欢迎大家<a href="https://mp.weixin.qq.com/s/tqCxrMEU-ajQumL1i8im9A">参与本项目</a>，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
|
||||
|
||||
## 226.翻转二叉树
|
||||
@ -247,10 +247,100 @@ func invertTree(root *TreeNode) *TreeNode {
|
||||
}
|
||||
```
|
||||
|
||||
JavaScript:
|
||||
|
||||
使用递归版本的前序遍历
|
||||
```javascript
|
||||
var invertTree = function(root) {
|
||||
//1. 首先使用递归版本的前序遍历实现二叉树翻转
|
||||
//交换节点函数
|
||||
const inverNode=function(left,right){
|
||||
let temp=left;
|
||||
left=right;
|
||||
right=temp;
|
||||
//需要重新给root赋值一下
|
||||
root.left=left;
|
||||
root.right=right;
|
||||
}
|
||||
//确定递归函数的参数和返回值inverTree=function(root)
|
||||
//确定终止条件
|
||||
if(root===null){
|
||||
return root;
|
||||
}
|
||||
//确定节点处理逻辑 交换
|
||||
inverNode(root.left,root.right);
|
||||
invertTree(root.left);
|
||||
invertTree(root.right);
|
||||
return root;
|
||||
};
|
||||
```
|
||||
使用迭代版本(统一模板))的前序遍历：
|
||||
```javascript
|
||||
var invertTree = function(root) {
|
||||
//我们先定义节点交换函数
|
||||
const invertNode=function(root,left,right){
|
||||
let temp=left;
|
||||
left=right;
|
||||
right=temp;
|
||||
root.left=left;
|
||||
root.right=right;
|
||||
}
|
||||
//使用迭代方法的前序遍历
|
||||
let stack=[];
|
||||
if(root===null){
|
||||
return root;
|
||||
}
|
||||
stack.push(root);
|
||||
while(stack.length){
|
||||
let node=stack.pop();
|
||||
if(node!==null){
|
||||
//前序遍历顺序中左右 入栈顺序是前序遍历的倒序右左中
|
||||
node.right&&stack.push(node.right);
|
||||
node.left&&stack.push(node.left);
|
||||
stack.push(node);
|
||||
stack.push(null);
|
||||
}else{
|
||||
node=stack.pop();
|
||||
//节点处理逻辑
|
||||
invertNode(node,node.left,node.right);
|
||||
}
|
||||
}
|
||||
return root;
|
||||
};
|
||||
```
|
||||
使用层序遍历：
|
||||
```javascript
|
||||
var invertTree = function(root) {
|
||||
//我们先定义节点交换函数
|
||||
const invertNode=function(root,left,right){
|
||||
let temp=left;
|
||||
left=right;
|
||||
right=temp;
|
||||
root.left=left;
|
||||
root.right=right;
|
||||
}
|
||||
//使用层序遍历
|
||||
let queue=[];
|
||||
if(root===null){
|
||||
return root;
|
||||
}
|
||||
queue.push(root);
|
||||
while(queue.length){
|
||||
let length=queue.length;
|
||||
while(length--){
|
||||
let node=queue.shift();
|
||||
//节点处理逻辑
|
||||
invertNode(node,node.left,node.right);
|
||||
node.left&&queue.push(node.left);
|
||||
node.right&&queue.push(node.right);
|
||||
}
|
||||
}
|
||||
return root;
|
||||
};
|
||||
```
|
||||
|
||||
-----------------------
|
||||
* 作者微信：[程序员Carl](https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw)
|
||||
* B站视频：[代码随想录](https://space.bilibili.com/525438321)
|
||||
* 知识星球：[代码随想录](https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ)
|
||||
<div align="center"><img src=../pics/公众号.png width=450 alt=> </img></div>
|
||||
<div align="center"><img src=../pics/公众号.png width=450 alt=> </img></div>
|
||||
|
||||
@ -1,10 +1,10 @@
|
||||
<p align="center">
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/RsdcQ9umo09R6cfnwXZlrQ"><img src="https://img.shields.io/badge/PDF下载-代码随想录-blueviolet" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw"><img src="https://img.shields.io/badge/刷题-微信群-green" alt=""></a>
|
||||
<a href="https://img-blog.csdnimg.cn/20201210231711160.png"><img src="https://img.shields.io/badge/公众号-代码随想录-brightgreen" alt=""></a>
|
||||
<a href="https://space.bilibili.com/525438321"><img src="https://img.shields.io/badge/B站-代码随想录-orange" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
</p>
|
||||
<p align="center"><strong>欢迎大家参与本项目，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
<p align="center"><strong>欢迎大家<a href="https://mp.weixin.qq.com/s/tqCxrMEU-ajQumL1i8im9A">参与本项目</a>，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
|
||||
|
||||
> 工作上一定没人这么搞，但是考察对栈、队列理解程度的好题
|
||||
@ -131,6 +131,101 @@ public:
|
||||
|
||||
Java：
|
||||
|
||||
使用Stack(堆栈)同名方法:
|
||||
```java
|
||||
class MyQueue {
|
||||
// java中的 Stack 有设计上的缺陷，官方推荐使用 Deque(双端队列) 代替 Stack
|
||||
Deque<Integer> stIn;
|
||||
Deque<Integer> stOut;
|
||||
/** Initialize your data structure here. */
|
||||
public MyQueue() {
|
||||
stIn = new ArrayDeque<>();
|
||||
stOut = new ArrayDeque<>();
|
||||
}
|
||||
|
||||
/** Push element x to the back of queue. */
|
||||
public void push(int x) {
|
||||
stIn.push(x);
|
||||
}
|
||||
|
||||
/** Removes the element from in front of queue and returns that element. */
|
||||
public int pop() {
|
||||
// 只要 stOut 为空，那么就应该将 stIn 中所有的元素倒腾到 stOut 中
|
||||
if (stOut.isEmpty()) {
|
||||
while (!stIn.isEmpty()) {
|
||||
stOut.push(stIn.pop());
|
||||
}
|
||||
}
|
||||
// 再返回 stOut 中的元素
|
||||
return stOut.pop();
|
||||
}
|
||||
|
||||
/** Get the front element. */
|
||||
public int peek() {
|
||||
// 直接使用已有的pop函数
|
||||
int res = this.pop();
|
||||
// 因为pop函数弹出了元素res，所以再添加回去
|
||||
stOut.push(res);
|
||||
return res;
|
||||
}
|
||||
|
||||
/** Returns whether the queue is empty. */
|
||||
public boolean empty() {
|
||||
// 当 stIn 栈为空时，说明没有元素可以倒腾到 stOut 栈了
|
||||
// 并且 stOut 栈也为空时，说明没有以前从 stIn 中倒腾到的元素了
|
||||
return stIn.isEmpty() && stOut.isEmpty();
|
||||
}
|
||||
}
|
||||
```
|
||||
|
||||
个人习惯写法，使用Deque通用api：
|
||||
```java
|
||||
class MyQueue {
|
||||
// java中的 Stack 有设计上的缺陷，官方推荐使用 Deque(双端队列) 代替 Stack
|
||||
// Deque 中的 addFirst、removeFirst、peekFirst 等方法等效于 Stack(堆栈) 中的 push、pop、peek
|
||||
Deque<Integer> stIn;
|
||||
Deque<Integer> stOut;
|
||||
/** Initialize your data structure here. */
|
||||
public MyQueue() {
|
||||
stIn = new ArrayDeque<>();
|
||||
stOut = new ArrayDeque<>();
|
||||
}
|
||||
|
||||
/** Push element x to the back of queue. */
|
||||
public void push(int x) {
|
||||
stIn.addLast(x);
|
||||
}
|
||||
|
||||
/** Removes the element from in front of queue and returns that element. */
|
||||
public int pop() {
|
||||
// 只要 stOut 为空，那么就应该将 stIn 中所有的元素倒腾到 stOut 中
|
||||
if (stOut.isEmpty()) {
|
||||
while (!stIn.isEmpty()) {
|
||||
stOut.addLast(stIn.pollLast());
|
||||
}
|
||||
}
|
||||
// 再返回 stOut 中的元素
|
||||
return stOut.pollLast();
|
||||
}
|
||||
|
||||
/** Get the front element. */
|
||||
public int peek() {
|
||||
// 直接使用已有的pop函数
|
||||
int res = this.pop();
|
||||
// 因为pop函数弹出了元素res，所以再添加回去
|
||||
stOut.addLast(res);
|
||||
return res;
|
||||
}
|
||||
|
||||
/** Returns whether the queue is empty. */
|
||||
public boolean empty() {
|
||||
// 当 stIn 栈为空时，说明没有元素可以倒腾到 stOut 栈了
|
||||
// 并且 stOut 栈也为空时，说明没有以前从 stIn 中倒腾到的元素了
|
||||
return stIn.isEmpty() && stOut.isEmpty();
|
||||
}
|
||||
}
|
||||
```
|
||||
|
||||
```java
|
||||
class MyQueue {
|
||||
|
||||
@ -190,6 +285,73 @@ Python：
|
||||
|
||||
|
||||
Go：
|
||||
```Go
|
||||
type MyQueue struct {
|
||||
stack []int
|
||||
back []int
|
||||
}
|
||||
|
||||
/** Initialize your data structure here. */
|
||||
func Constructor() MyQueue {
|
||||
return MyQueue{
|
||||
stack: make([]int, 0),
|
||||
back: make([]int, 0),
|
||||
}
|
||||
}
|
||||
|
||||
/** Push element x to the back of queue. */
|
||||
func (this *MyQueue) Push(x int) {
|
||||
for len(this.back) != 0 {
|
||||
val := this.back[len(this.back)-1]
|
||||
this.back = this.back[:len(this.back)-1]
|
||||
this.stack = append(this.stack, val)
|
||||
}
|
||||
this.stack = append(this.stack, x)
|
||||
}
|
||||
|
||||
/** Removes the element from in front of queue and returns that element. */
|
||||
func (this *MyQueue) Pop() int {
|
||||
for len(this.stack) != 0 {
|
||||
val := this.stack[len(this.stack)-1]
|
||||
this.stack = this.stack[:len(this.stack)-1]
|
||||
this.back = append(this.back, val)
|
||||
}
|
||||
if len(this.back) == 0 {
|
||||
return 0
|
||||
}
|
||||
val := this.back[len(this.back)-1]
|
||||
this.back = this.back[:len(this.back)-1]
|
||||
return val
|
||||
}
|
||||
|
||||
/** Get the front element. */
|
||||
func (this *MyQueue) Peek() int {
|
||||
for len(this.stack) != 0 {
|
||||
val := this.stack[len(this.stack)-1]
|
||||
this.stack = this.stack[:len(this.stack)-1]
|
||||
this.back = append(this.back, val)
|
||||
}
|
||||
if len(this.back) == 0 {
|
||||
return 0
|
||||
}
|
||||
val := this.back[len(this.back)-1]
|
||||
return val
|
||||
}
|
||||
|
||||
/** Returns whether the queue is empty. */
|
||||
func (this *MyQueue) Empty() bool {
|
||||
return len(this.stack) == 0 && len(this.back) == 0
|
||||
}
|
||||
|
||||
/**
|
||||
* Your MyQueue object will be instantiated and called as such:
|
||||
* obj := Constructor();
|
||||
* obj.Push(x);
|
||||
* param_2 := obj.Pop();
|
||||
* param_3 := obj.Peek();
|
||||
* param_4 := obj.Empty();
|
||||
*/
|
||||
```
|
||||
|
||||
|
||||
|
||||
@ -198,4 +360,4 @@ Go：
|
||||
* 作者微信：[程序员Carl](https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw)
|
||||
* B站视频：[代码随想录](https://space.bilibili.com/525438321)
|
||||
* 知识星球：[代码随想录](https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ)
|
||||
<div align="center"><img src=../pics/公众号.png width=450 alt=> </img></div>
|
||||
<div align="center"><img src=../pics/公众号.png width=450 alt=> </img></div>
|
||||
|
||||
@ -1,10 +1,10 @@
|
||||
<p align="center">
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/RsdcQ9umo09R6cfnwXZlrQ"><img src="https://img.shields.io/badge/PDF下载-代码随想录-blueviolet" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw"><img src="https://img.shields.io/badge/刷题-微信群-green" alt=""></a>
|
||||
<a href="https://img-blog.csdnimg.cn/20201210231711160.png"><img src="https://img.shields.io/badge/公众号-代码随想录-brightgreen" alt=""></a>
|
||||
<a href="https://space.bilibili.com/525438321"><img src="https://img.shields.io/badge/B站-代码随想录-orange" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
</p>
|
||||
<p align="center"><strong>欢迎大家参与本项目，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
<p align="center"><strong>欢迎大家<a href="https://mp.weixin.qq.com/s/tqCxrMEU-ajQumL1i8im9A">参与本项目</a>，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
|
||||
|
||||
## 235. 二叉搜索树的最近公共祖先
|
||||
@ -247,8 +247,23 @@ class Solution {
|
||||
```
|
||||
|
||||
Python：
|
||||
```python
|
||||
# Definition for a binary tree node.
|
||||
# class TreeNode:
|
||||
# def __init__(self, x):
|
||||
# self.val = x
|
||||
# self.left = None
|
||||
# self.right = None
|
||||
|
||||
|
||||
class Solution:
|
||||
def lowestCommonAncestor(self, root: 'TreeNode', p: 'TreeNode', q: 'TreeNode') -> 'TreeNode':
|
||||
if not root: return root //中
|
||||
if root.val >p.val and root.val > q.val:
|
||||
return self.lowestCommonAncestor(root.left,p,q) //左
|
||||
elif root.val < p.val and root.val < q.val:
|
||||
return self.lowestCommonAncestor(root.right,p,q) //右
|
||||
else: return root
|
||||
```
|
||||
Go：
|
||||
|
||||
|
||||
@ -258,4 +273,4 @@ Go：
|
||||
* 作者微信：[程序员Carl](https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw)
|
||||
* B站视频：[代码随想录](https://space.bilibili.com/525438321)
|
||||
* 知识星球：[代码随想录](https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ)
|
||||
<div align="center"><img src=../pics/公众号.png width=450 alt=> </img></div>
|
||||
<div align="center"><img src=../pics/公众号.png width=450 alt=> </img></div>
|
||||
|
||||
@ -1,10 +1,10 @@
|
||||
<p align="center">
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/RsdcQ9umo09R6cfnwXZlrQ"><img src="https://img.shields.io/badge/PDF下载-代码随想录-blueviolet" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw"><img src="https://img.shields.io/badge/刷题-微信群-green" alt=""></a>
|
||||
<a href="https://img-blog.csdnimg.cn/20201210231711160.png"><img src="https://img.shields.io/badge/公众号-代码随想录-brightgreen" alt=""></a>
|
||||
<a href="https://space.bilibili.com/525438321"><img src="https://img.shields.io/badge/B站-代码随想录-orange" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
</p>
|
||||
<p align="center"><strong>欢迎大家参与本项目，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
<p align="center"><strong>欢迎大家<a href="https://mp.weixin.qq.com/s/tqCxrMEU-ajQumL1i8im9A">参与本项目</a>，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
|
||||
|
||||
> 本来是打算将二叉树和二叉搜索树的公共祖先问题一起讲，后来发现篇幅过长了，只能先说一说二叉树的公共祖先问题。
|
||||
@ -263,10 +263,53 @@ class Solution {
|
||||
```
|
||||
|
||||
Python：
|
||||
|
||||
|
||||
```python
|
||||
# Definition for a binary tree node.
|
||||
# class TreeNode:
|
||||
# def __init__(self, x):
|
||||
# self.val = x
|
||||
# self.left = None
|
||||
# self.right = None
|
||||
//递归
|
||||
class Solution:
|
||||
def lowestCommonAncestor(self, root: 'TreeNode', p: 'TreeNode', q: 'TreeNode') -> 'TreeNode':
|
||||
if not root or root == p or root == q: return root //找到了节点p或者q，或者遇到空节点
|
||||
left = self.lowestCommonAncestor(root.left,p,q) //左
|
||||
right = self.lowestCommonAncestor(root.right,p,q) //右
|
||||
if left and right: return root //中: left和right不为空，root就是最近公共节点
|
||||
elif left and not right: return left //目标节点是通过left返回的
|
||||
elif not left and right: return right //目标节点是通过right返回的
|
||||
else: return None //没找到
|
||||
```
|
||||
Go：
|
||||
```Go
|
||||
func lowestCommonAncestor(root, p, q *TreeNode) *TreeNode {
|
||||
// check
|
||||
if root == nil {
|
||||
return root
|
||||
}
|
||||
// 相等 直接返回root节点即可
|
||||
if root == p || root == q {
|
||||
return root
|
||||
}
|
||||
// Divide
|
||||
left := lowestCommonAncestor(root.Left, p, q)
|
||||
right := lowestCommonAncestor(root.Right, p, q)
|
||||
|
||||
// Conquer
|
||||
// 左右两边都不为空，则根节点为祖先
|
||||
if left != nil && right != nil {
|
||||
return root
|
||||
}
|
||||
if left != nil {
|
||||
return left
|
||||
}
|
||||
if right != nil {
|
||||
return right
|
||||
}
|
||||
return nil
|
||||
}
|
||||
```
|
||||
|
||||
|
||||
|
||||
@ -274,4 +317,4 @@ Go：
|
||||
* 作者微信：[程序员Carl](https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw)
|
||||
* B站视频：[代码随想录](https://space.bilibili.com/525438321)
|
||||
* 知识星球：[代码随想录](https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ)
|
||||
<div align="center"><img src=../pics/公众号.png width=450 alt=> </img></div>
|
||||
<div align="center"><img src=../pics/公众号.png width=450 alt=> </img></div>
|
||||
|
||||
@ -1,10 +1,10 @@
|
||||
<p align="center">
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/RsdcQ9umo09R6cfnwXZlrQ"><img src="https://img.shields.io/badge/PDF下载-代码随想录-blueviolet" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw"><img src="https://img.shields.io/badge/刷题-微信群-green" alt=""></a>
|
||||
<a href="https://img-blog.csdnimg.cn/20201210231711160.png"><img src="https://img.shields.io/badge/公众号-代码随想录-brightgreen" alt=""></a>
|
||||
<a href="https://space.bilibili.com/525438321"><img src="https://img.shields.io/badge/B站-代码随想录-orange" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
</p>
|
||||
<p align="center"><strong>欢迎大家参与本项目，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
<p align="center"><strong>欢迎大家<a href="https://mp.weixin.qq.com/s/tqCxrMEU-ajQumL1i8im9A">参与本项目</a>，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
|
||||
|
||||
|
||||
@ -267,7 +267,30 @@ Python：
|
||||
|
||||
Go：
|
||||
|
||||
|
||||
Javascript:
|
||||
```javascript
|
||||
var maxSlidingWindow = function (nums, k) {
|
||||
// 队列数组（存放的是元素下标，为了取值方便）
|
||||
const q = [];
|
||||
// 结果数组
|
||||
const ans = [];
|
||||
for (let i = 0; i < nums.length; i++) {
|
||||
// 若队列不为空，且当前元素大于等于队尾所存下标的元素，则弹出队尾
|
||||
while (q.length && nums[i] >= nums[q[q.length - 1]]) {
|
||||
q.pop();
|
||||
}
|
||||
// 入队当前元素下标
|
||||
q.push(i);
|
||||
// 判断当前最大值（即队首元素）是否在窗口中，若不在便将其出队
|
||||
while (q[0] <= i - k) {
|
||||
q.shift();
|
||||
}
|
||||
// 当达到窗口大小时便开始向结果中添加数据
|
||||
if (i >= k - 1) ans.push(nums[q[0]]);
|
||||
}
|
||||
return ans;
|
||||
};
|
||||
```
|
||||
|
||||
|
||||
-----------------------
|
||||
|
||||
@ -1,26 +1,33 @@
|
||||
<p align="center">
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/RsdcQ9umo09R6cfnwXZlrQ"><img src="https://img.shields.io/badge/PDF下载-代码随想录-blueviolet" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw"><img src="https://img.shields.io/badge/刷题-微信群-green" alt=""></a>
|
||||
<a href="https://img-blog.csdnimg.cn/20201210231711160.png"><img src="https://img.shields.io/badge/公众号-代码随想录-brightgreen" alt=""></a>
|
||||
<a href="https://space.bilibili.com/525438321"><img src="https://img.shields.io/badge/B站-代码随想录-orange" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
</p>
|
||||
<p align="center"><strong>欢迎大家参与本项目，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
<p align="center"><strong>欢迎大家<a href="https://mp.weixin.qq.com/s/tqCxrMEU-ajQumL1i8im9A">参与本项目</a>，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
|
||||
|
||||
> 数组就是简单的哈希表，但是数组的大小可不是无限开辟的
|
||||
|
||||
# 242.有效的字母异位词
|
||||
## 242.有效的字母异位词
|
||||
|
||||
https://leetcode-cn.com/problems/valid-anagram/
|
||||
|
||||
给定两个字符串 s 和 t ，编写一个函数来判断 t 是否是 s 的字母异位词。
|
||||
|
||||
|
||||
示例 1:
|
||||
输入: s = "anagram", t = "nagaram"
|
||||
输出: true
|
||||
|
||||
示例 2:
|
||||
输入: s = "rat", t = "car"
|
||||
输出: false
|
||||
|
||||
|
||||
**说明:**
|
||||
你可以假设字符串只包含小写字母。
|
||||
|
||||
# 思路
|
||||
## 思路
|
||||
|
||||
先看暴力的解法，两层for循环，同时还要记录字符是否重复出现，很明显时间复杂度是 O(n^2)。
|
||||
|
||||
@ -52,7 +59,6 @@ https://leetcode-cn.com/problems/valid-anagram/
|
||||
|
||||
时间复杂度为O(n)，空间上因为定义是的一个常量大小的辅助数组，所以空间复杂度为O(1)。
|
||||
|
||||
看完这篇哈希表总结：[哈希表：总结篇！（每逢总结必经典）](https://mp.weixin.qq.com/s/1s91yXtarL-PkX07BfnwLg)，详细就可以哈希表的各种用法非常清晰了。
|
||||
|
||||
C++ 代码如下：
|
||||
```C++
|
||||
@ -134,9 +140,38 @@ func isAnagram(s string, t string) bool {
|
||||
}
|
||||
```
|
||||
|
||||
javaScript:
|
||||
|
||||
```js
|
||||
/**
|
||||
* @param {string} s
|
||||
* @param {string} t
|
||||
* @return {boolean}
|
||||
*/
|
||||
var isAnagram = function(s, t) {
|
||||
if(s.length !== t.length) return false;
|
||||
const resSet = new Array(26).fill(0);
|
||||
const base = "a".charCodeAt();
|
||||
for(const i of s) {
|
||||
resSet[i.charCodeAt() - base]++;
|
||||
}
|
||||
for(const i of t) {
|
||||
if(!resSet[i.charCodeAt() - base]) return false;
|
||||
resSet[i.charCodeAt() - base]--;
|
||||
}
|
||||
return true;
|
||||
};
|
||||
```
|
||||
|
||||
## 相关题目
|
||||
|
||||
* 383.赎金信
|
||||
* 49.字母异位词分组
|
||||
* 438.找到字符串中所有字母异位词
|
||||
|
||||
|
||||
-----------------------
|
||||
* 作者微信：[程序员Carl](https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw)
|
||||
* B站视频：[代码随想录](https://space.bilibili.com/525438321)
|
||||
* 知识星球：[代码随想录](https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ)
|
||||
<div align="center"><img src=../pics/公众号.png width=450 alt=> </img></div>
|
||||
<div align="center"><img src=../pics/公众号.png width=450 alt=> </img></div>
|
||||
|
||||
@ -1,10 +1,10 @@
|
||||
<p align="center">
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/RsdcQ9umo09R6cfnwXZlrQ"><img src="https://img.shields.io/badge/PDF下载-代码随想录-blueviolet" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw"><img src="https://img.shields.io/badge/刷题-微信群-green" alt=""></a>
|
||||
<a href="https://img-blog.csdnimg.cn/20201210231711160.png"><img src="https://img.shields.io/badge/公众号-代码随想录-brightgreen" alt=""></a>
|
||||
<a href="https://space.bilibili.com/525438321"><img src="https://img.shields.io/badge/B站-代码随想录-orange" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
</p>
|
||||
<p align="center"><strong>欢迎大家参与本项目，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
<p align="center"><strong>欢迎大家<a href="https://mp.weixin.qq.com/s/tqCxrMEU-ajQumL1i8im9A">参与本项目</a>，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
|
||||
|
||||
> 以为只用了递归，其实还用了回溯
|
||||
@ -77,7 +77,7 @@ if (cur->left == NULL && cur->right == NULL) {
|
||||
|
||||
这里我们先使用vector<int>结构的path容器来记录路径，那么终止处理逻辑如下：
|
||||
|
||||
```
|
||||
```C++
|
||||
if (cur->left == NULL && cur->right == NULL) { // 遇到叶子节点
|
||||
string sPath;
|
||||
for (int i = 0; i < path.size() - 1; i++) { // 将path里记录的路径转为string格式
|
||||
@ -113,7 +113,7 @@ if (cur->right) {
|
||||
|
||||
那么回溯要怎么回溯呢，一些同学会这么写，如下：
|
||||
|
||||
```
|
||||
```C++
|
||||
if (cur->left) {
|
||||
traversal(cur->left, path, result);
|
||||
}
|
||||
@ -129,7 +129,7 @@ path.pop_back();
|
||||
|
||||
那么代码应该这么写：
|
||||
|
||||
```
|
||||
```C++
|
||||
if (cur->left) {
|
||||
traversal(cur->left, path, result);
|
||||
path.pop_back(); // 回溯
|
||||
@ -324,8 +324,31 @@ class Solution {
|
||||
```
|
||||
|
||||
Python：
|
||||
```Python
|
||||
# class TreeNode:
|
||||
# def __init__(self, val=0, left=None, right=None):
|
||||
# self.val = val
|
||||
# self.left = left
|
||||
# self.right = right
|
||||
class Solution:
|
||||
def binaryTreePaths(self, root: TreeNode) -> List[str]:
|
||||
path=[]
|
||||
res=[]
|
||||
def backtrace(root, path):
|
||||
if not root:return
|
||||
path.append(root.val)
|
||||
if (not root.left)and (not root.right):
|
||||
res.append(path[:])
|
||||
ways=[]
|
||||
if root.left:ways.append(root.left)
|
||||
if root.right:ways.append(root.right)
|
||||
for way in ways:
|
||||
backtrace(way,path)
|
||||
path.pop()
|
||||
backtrace(root,path)
|
||||
return ["->".join(list(map(str,i))) for i in res]
|
||||
|
||||
|
||||
```
|
||||
Go：
|
||||
|
||||
|
||||
@ -335,4 +358,4 @@ Go：
|
||||
* 作者微信：[程序员Carl](https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw)
|
||||
* B站视频：[代码随想录](https://space.bilibili.com/525438321)
|
||||
* 知识星球：[代码随想录](https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ)
|
||||
<div align="center"><img src=../pics/公众号.png width=450 alt=> </img></div>
|
||||
<div align="center"><img src=../pics/公众号.png width=450 alt=> </img></div>
|
||||
|
||||
@ -1,10 +1,10 @@
|
||||
<p align="center">
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/RsdcQ9umo09R6cfnwXZlrQ"><img src="https://img.shields.io/badge/PDF下载-代码随想录-blueviolet" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw"><img src="https://img.shields.io/badge/刷题-微信群-green" alt=""></a>
|
||||
<a href="https://img-blog.csdnimg.cn/20201210231711160.png"><img src="https://img.shields.io/badge/公众号-代码随想录-brightgreen" alt=""></a>
|
||||
<a href="https://space.bilibili.com/525438321"><img src="https://img.shields.io/badge/B站-代码随想录-orange" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
</p>
|
||||
<p align="center"><strong>欢迎大家参与本项目，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
<p align="center"><strong>欢迎大家<a href="https://mp.weixin.qq.com/s/tqCxrMEU-ajQumL1i8im9A">参与本项目</a>，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
# 动态规划：一样的套路，再求一次完全平方数
|
||||
|
||||
## 279.完全平方数
|
||||
|
||||
@ -1,10 +1,10 @@
|
||||
<p align="center">
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/RsdcQ9umo09R6cfnwXZlrQ"><img src="https://img.shields.io/badge/PDF下载-代码随想录-blueviolet" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw"><img src="https://img.shields.io/badge/刷题-微信群-green" alt=""></a>
|
||||
<a href="https://img-blog.csdnimg.cn/20201210231711160.png"><img src="https://img.shields.io/badge/公众号-代码随想录-brightgreen" alt=""></a>
|
||||
<a href="https://space.bilibili.com/525438321"><img src="https://img.shields.io/badge/B站-代码随想录-orange" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
</p>
|
||||
<p align="center"><strong>欢迎大家参与本项目，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
<p align="center"><strong>欢迎大家<a href="https://mp.weixin.qq.com/s/tqCxrMEU-ajQumL1i8im9A">参与本项目</a>，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
|
||||
## 300.最长递增子序列
|
||||
|
||||
@ -98,8 +98,6 @@ public:
|
||||
};
|
||||
```
|
||||
|
||||
杨老师的这个专栏很不错，他本身也是Oracle 首席工程师，对Java有极其深刻的理解，讲的内容很硬核，适合使用Java语言的录友们用来进阶！作为面试突击手册非常合适， 所以推荐给大家！现在下单输入口令：javahexin，可以省40元那[机智]
|
||||
|
||||
## 总结
|
||||
|
||||
本题最关键的是要想到dp[i]由哪些状态可以推出来，并取最大值，那么很自然就能想到递推公式：dp[i] = max(dp[i], dp[j] + 1);
|
||||
@ -135,8 +133,33 @@ Python：
|
||||
|
||||
|
||||
Go：
|
||||
|
||||
|
||||
```go
|
||||
func lengthOfLIS(nums []int ) int {
|
||||
dp := []int{}
|
||||
for _, num := range nums {
|
||||
if len(dp) ==0 || dp[len(dp) - 1] < num {
|
||||
dp = append(dp, num)
|
||||
} else {
|
||||
l, r := 0, len(dp) - 1
|
||||
pos := r
|
||||
for l <= r {
|
||||
mid := (l + r) >> 1
|
||||
if dp[mid] >= num {
|
||||
pos = mid;
|
||||
r = mid - 1
|
||||
} else {
|
||||
l = mid + 1
|
||||
}
|
||||
}
|
||||
dp[pos] = num
|
||||
}//二分查找
|
||||
}
|
||||
return len(dp)
|
||||
}
|
||||
```
|
||||
*复杂度分析*
|
||||
- 时间复杂度：O(nlogn)。数组 nums 的长度为 n，我们依次用数组中的元素去更新 dp 数组，相当于插入最后递增的元素，而更新 dp 数组时需要进行 O(logn) 的二分搜索，所以总时间复杂度为 O(nlogn)。
|
||||
- 空间复杂度：O(n)，需要额外使用长度为 n 的 dp 数组。
|
||||
|
||||
|
||||
-----------------------
|
||||
|
||||
@ -1,10 +1,10 @@
|
||||
<p align="center">
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/RsdcQ9umo09R6cfnwXZlrQ"><img src="https://img.shields.io/badge/PDF下载-代码随想录-blueviolet" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw"><img src="https://img.shields.io/badge/刷题-微信群-green" alt=""></a>
|
||||
<a href="https://img-blog.csdnimg.cn/20201210231711160.png"><img src="https://img.shields.io/badge/公众号-代码随想录-brightgreen" alt=""></a>
|
||||
<a href="https://space.bilibili.com/525438321"><img src="https://img.shields.io/badge/B站-代码随想录-orange" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
</p>
|
||||
<p align="center"><strong>欢迎大家参与本项目，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
<p align="center"><strong>欢迎大家<a href="https://mp.weixin.qq.com/s/tqCxrMEU-ajQumL1i8im9A">参与本项目</a>，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
|
||||
## 309.最佳买卖股票时机含冷冻期
|
||||
|
||||
@ -159,9 +159,33 @@ public:
|
||||
|
||||
## 其他语言版本
|
||||
|
||||
|
||||
Java：
|
||||
|
||||
```java
|
||||
class Solution {
|
||||
public int maxProfit(int[] prices) {
|
||||
if (prices == null || prices.length < 2) {
|
||||
return 0;
|
||||
}
|
||||
int[][] dp = new int[prices.length][2];
|
||||
|
||||
// bad case
|
||||
dp[0][0] = 0;
|
||||
dp[0][1] = -prices[0];
|
||||
dp[1][0] = Math.max(dp[0][0], dp[0][1] + prices[1]);
|
||||
dp[1][1] = Math.max(dp[0][1], -prices[1]);
|
||||
|
||||
for (int i = 2; i < prices.length; i++) {
|
||||
// dp公式
|
||||
dp[i][0] = Math.max(dp[i - 1][0], dp[i - 1][1] + prices[i]);
|
||||
dp[i][1] = Math.max(dp[i - 1][1], dp[i - 2][0] - prices[i]);
|
||||
}
|
||||
|
||||
return dp[prices.length - 1][0];
|
||||
}
|
||||
}
|
||||
```
|
||||
|
||||
|
||||
Python：
|
||||
|
||||
|
||||
@ -1,10 +1,10 @@
|
||||
<p align="center">
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/RsdcQ9umo09R6cfnwXZlrQ"><img src="https://img.shields.io/badge/PDF下载-代码随想录-blueviolet" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw"><img src="https://img.shields.io/badge/刷题-微信群-green" alt=""></a>
|
||||
<a href="https://img-blog.csdnimg.cn/20201210231711160.png"><img src="https://img.shields.io/badge/公众号-代码随想录-brightgreen" alt=""></a>
|
||||
<a href="https://space.bilibili.com/525438321"><img src="https://img.shields.io/badge/B站-代码随想录-orange" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
</p>
|
||||
<p align="center"><strong>欢迎大家参与本项目，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
<p align="center"><strong>欢迎大家<a href="https://mp.weixin.qq.com/s/tqCxrMEU-ajQumL1i8im9A">参与本项目</a>，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
# 动态规划： 给我个机会，我再兑换一次零钱
|
||||
|
||||
## 322. 零钱兑换
|
||||
|
||||
@ -1,10 +1,10 @@
|
||||
<p align="center">
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/RsdcQ9umo09R6cfnwXZlrQ"><img src="https://img.shields.io/badge/PDF下载-代码随想录-blueviolet" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw"><img src="https://img.shields.io/badge/刷题-微信群-green" alt=""></a>
|
||||
<a href="https://img-blog.csdnimg.cn/20201210231711160.png"><img src="https://img.shields.io/badge/公众号-代码随想录-brightgreen" alt=""></a>
|
||||
<a href="https://space.bilibili.com/525438321"><img src="https://img.shields.io/badge/B站-代码随想录-orange" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
</p>
|
||||
<p align="center"><strong>欢迎大家参与本项目，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
<p align="center"><strong>欢迎大家<a href="https://mp.weixin.qq.com/s/tqCxrMEU-ajQumL1i8im9A">参与本项目</a>，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
|
||||
|
||||
> 这也可以用回溯法？ 其实深搜和回溯也是相辅相成的，毕竟都用递归。
|
||||
@ -399,6 +399,49 @@ char ** findItinerary(char *** tickets, int ticketsSize, int* ticketsColSize, in
|
||||
}
|
||||
```
|
||||
|
||||
Javascript:
|
||||
```Javascript
|
||||
|
||||
var findItinerary = function(tickets) {
|
||||
let result = ['JFK']
|
||||
let map = {}
|
||||
|
||||
for (const tickt of tickets) {
|
||||
const [from, to] = tickt
|
||||
if (!map[from]) {
|
||||
map[from] = []
|
||||
}
|
||||
map[from].push(to)
|
||||
}
|
||||
|
||||
for (const city in map) {
|
||||
// 对到达城市列表排序
|
||||
map[city].sort()
|
||||
}
|
||||
function backtracing() {
|
||||
if (result.length === tickets.length + 1) {
|
||||
return true
|
||||
}
|
||||
if (!map[result[result.length - 1]] || !map[result[result.length - 1]].length) {
|
||||
return false
|
||||
}
|
||||
for(let i = 0 ; i < map[result[result.length - 1]].length; i++) {
|
||||
let city = map[result[result.length - 1]][i]
|
||||
// 删除已走过航线，防止死循环
|
||||
map[result[result.length - 1]].splice(i, 1)
|
||||
result.push(city)
|
||||
if (backtracing()) {
|
||||
return true
|
||||
}
|
||||
result.pop()
|
||||
map[result[result.length - 1]].splice(i, 0, city)
|
||||
}
|
||||
}
|
||||
backtracing()
|
||||
return result
|
||||
};
|
||||
|
||||
```
|
||||
|
||||
-----------------------
|
||||
* 作者微信：[程序员Carl](https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw)
|
||||
|
||||
@ -1,10 +1,10 @@
|
||||
<p align="center">
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/RsdcQ9umo09R6cfnwXZlrQ"><img src="https://img.shields.io/badge/PDF下载-代码随想录-blueviolet" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw"><img src="https://img.shields.io/badge/刷题-微信群-green" alt=""></a>
|
||||
<a href="https://img-blog.csdnimg.cn/20201210231711160.png"><img src="https://img.shields.io/badge/公众号-代码随想录-brightgreen" alt=""></a>
|
||||
<a href="https://space.bilibili.com/525438321"><img src="https://img.shields.io/badge/B站-代码随想录-orange" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
</p>
|
||||
<p align="center"><strong>欢迎大家参与本项目，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
<p align="center"><strong>欢迎大家<a href="https://mp.weixin.qq.com/s/tqCxrMEU-ajQumL1i8im9A">参与本项目</a>，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
|
||||
|
||||
## 337.打家劫舍 III
|
||||
|
||||
@ -1,13 +1,15 @@
|
||||
<p align="center">
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/RsdcQ9umo09R6cfnwXZlrQ"><img src="https://img.shields.io/badge/PDF下载-代码随想录-blueviolet" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw"><img src="https://img.shields.io/badge/刷题-微信群-green" alt=""></a>
|
||||
<a href="https://img-blog.csdnimg.cn/20201210231711160.png"><img src="https://img.shields.io/badge/公众号-代码随想录-brightgreen" alt=""></a>
|
||||
<a href="https://space.bilibili.com/525438321"><img src="https://img.shields.io/badge/B站-代码随想录-orange" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
</p>
|
||||
<p align="center"><strong>欢迎大家参与本项目，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
<p align="center"><strong>欢迎大家<a href="https://mp.weixin.qq.com/s/tqCxrMEU-ajQumL1i8im9A">参与本项目</a>，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
|
||||
## 343. 整数拆分
|
||||
|
||||
题目链接：https://leetcode-cn.com/problems/integer-break/
|
||||
|
||||
给定一个正整数 n，将其拆分为至少两个正整数的和，并使这些整数的乘积最大化。 返回你可以获得的最大乘积。
|
||||
|
||||
示例 1:
|
||||
@ -51,9 +53,16 @@ dp[i]的定义讲贯彻整个解题过程，下面哪一步想不懂了，就想
|
||||
|
||||
j是从1开始遍历，拆分j的情况，在遍历j的过程中其实都计算过了。
|
||||
|
||||
那么从1遍历j，比较(i - j) * j和dp[i - j] * j 取最大的。
|
||||
**那有同学问了，j怎么就不拆分呢？**
|
||||
|
||||
j是从1开始遍历，拆分j的情况，在遍历j的过程中其实都计算过了。那么从1遍历j，比较(i - j) * j和dp[i - j] * j 取最大的。递推公式：dp[i] = max(dp[i], max((i - j) * j, dp[i - j] * j));
|
||||
|
||||
也可以这么理解，j * (i - j) 是单纯的把整数拆分为两个数相乘，而j * dp[i - j]是拆分成两个以及两个以上的个数相乘。
|
||||
|
||||
如果定义dp[i - j] * dp[j] 也是默认将一个数强制拆成4份以及4份以上了。
|
||||
|
||||
所以递推公式：dp[i] = max({dp[i], (i - j) * j, dp[i - j] * j});
|
||||
|
||||
递推公式：dp[i] = max(dp[i], max((i - j) * j, dp[i - j] * j));
|
||||
|
||||
3. dp的初始化
|
||||
|
||||
|
||||
@ -1,10 +1,10 @@
|
||||
<p align="center">
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/RsdcQ9umo09R6cfnwXZlrQ"><img src="https://img.shields.io/badge/PDF下载-代码随想录-blueviolet" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw"><img src="https://img.shields.io/badge/刷题-微信群-green" alt=""></a>
|
||||
<a href="https://img-blog.csdnimg.cn/20201210231711160.png"><img src="https://img.shields.io/badge/公众号-代码随想录-brightgreen" alt=""></a>
|
||||
<a href="https://space.bilibili.com/525438321"><img src="https://img.shields.io/badge/B站-代码随想录-orange" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
</p>
|
||||
<p align="center"><strong>欢迎大家参与本项目，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
<p align="center"><strong>欢迎大家<a href="https://mp.weixin.qq.com/s/tqCxrMEU-ajQumL1i8im9A">参与本项目</a>，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
|
||||
|
||||
|
||||
@ -157,7 +157,18 @@ class Solution {
|
||||
```
|
||||
|
||||
Python：
|
||||
|
||||
```python3
|
||||
class Solution:
|
||||
def reverseString(self, s: List[str]) -> None:
|
||||
"""
|
||||
Do not return anything, modify s in-place instead.
|
||||
"""
|
||||
left, right = 0, len(s) - 1
|
||||
while(left < right):
|
||||
s[left], s[right] = s[right], s[left]
|
||||
left += 1
|
||||
right -= 1
|
||||
```
|
||||
|
||||
Go：
|
||||
```Go
|
||||
|
||||
@ -1,10 +1,10 @@
|
||||
<p align="center">
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/RsdcQ9umo09R6cfnwXZlrQ"><img src="https://img.shields.io/badge/PDF下载-代码随想录-blueviolet" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw"><img src="https://img.shields.io/badge/刷题-微信群-green" alt=""></a>
|
||||
<a href="https://img-blog.csdnimg.cn/20201210231711160.png"><img src="https://img.shields.io/badge/公众号-代码随想录-brightgreen" alt=""></a>
|
||||
<a href="https://space.bilibili.com/525438321"><img src="https://img.shields.io/badge/B站-代码随想录-orange" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
</p>
|
||||
<p align="center"><strong>欢迎大家参与本项目，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
<p align="center"><strong>欢迎大家<a href="https://mp.weixin.qq.com/s/tqCxrMEU-ajQumL1i8im9A">参与本项目</a>，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
|
||||
|
||||
|
||||
|
||||
@ -1,17 +1,18 @@
|
||||
<p align="center">
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/RsdcQ9umo09R6cfnwXZlrQ"><img src="https://img.shields.io/badge/PDF下载-代码随想录-blueviolet" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw"><img src="https://img.shields.io/badge/刷题-微信群-green" alt=""></a>
|
||||
<a href="https://img-blog.csdnimg.cn/20201210231711160.png"><img src="https://img.shields.io/badge/公众号-代码随想录-brightgreen" alt=""></a>
|
||||
<a href="https://space.bilibili.com/525438321"><img src="https://img.shields.io/badge/B站-代码随想录-orange" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
</p>
|
||||
<p align="center"><strong>欢迎大家参与本项目，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
<p align="center"><strong>欢迎大家<a href="https://mp.weixin.qq.com/s/tqCxrMEU-ajQumL1i8im9A">参与本项目</a>，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
|
||||
|
||||
|
||||
|
||||
> 如果哈希值比较少、特别分散、跨度非常大，使用数组就造成空间的极大浪费！
|
||||
|
||||
# 349. 两个数组的交集
|
||||
|
||||
## 349. 两个数组的交集
|
||||
|
||||
https://leetcode-cn.com/problems/intersection-of-two-arrays/
|
||||
|
||||
@ -23,7 +24,7 @@ https://leetcode-cn.com/problems/intersection-of-two-arrays/
|
||||
输出结果中的每个元素一定是唯一的。
|
||||
我们可以不考虑输出结果的顺序。
|
||||
|
||||
# 思路
|
||||
## 思路
|
||||
|
||||
这道题目，主要要学会使用一种哈希数据结构：unordered_set，这个数据结构可以解决很多类似的问题。
|
||||
|
||||
@ -31,7 +32,7 @@ https://leetcode-cn.com/problems/intersection-of-two-arrays/
|
||||
|
||||
这道题用暴力的解法时间复杂度是O(n^2)，那来看看使用哈希法进一步优化。
|
||||
|
||||
那么用数组来做哈希表也是不错的选择，例如[242. 有效的字母异位词](https://mp.weixin.qq.com/s/vM6OszkM6L1Mx2Ralm9Dig)，[0383.赎金信](https://mp.weixin.qq.com/s/sYZIR4dFBrw_lr3eJJnteQ)
|
||||
那么用数组来做哈希表也是不错的选择，例如[242. 有效的字母异位词](https://mp.weixin.qq.com/s/ffS8jaVFNUWyfn_8T31IdA)
|
||||
|
||||
但是要注意，**使用数组来做哈希的题目，是因为题目都限制了数值的大小。**
|
||||
|
||||
@ -52,6 +53,7 @@ std::set和std::multiset底层实现都是红黑树，std::unordered_set的底
|
||||
|
||||
|
||||
C++代码如下：
|
||||
|
||||
```C++
|
||||
class Solution {
|
||||
public:
|
||||
@ -69,6 +71,13 @@ public:
|
||||
};
|
||||
```
|
||||
|
||||
## 拓展
|
||||
|
||||
那有同学可能问了，遇到哈希问题我直接都用set不就得了，用什么数组啊。
|
||||
|
||||
直接使用set 不仅占用空间比数组大，而且速度要比数组慢，set把数值映射到key上都要做hash计算的。
|
||||
|
||||
不要小瞧 这个耗时，在数据量大的情况，差距是很明显的。
|
||||
|
||||
|
||||
## 其他语言版本
|
||||
@ -113,7 +122,38 @@ Python：
|
||||
|
||||
Go：
|
||||
|
||||
javaScript:
|
||||
|
||||
```js
|
||||
/**
|
||||
* @param {number[]} nums1
|
||||
* @param {number[]} nums2
|
||||
* @return {number[]}
|
||||
*/
|
||||
var intersection = function(nums1, nums2) {
|
||||
// 根据数组大小交换操作的数组
|
||||
if(nums1.length < nums2.length) {
|
||||
const _ = nums1;
|
||||
nums1 = nums2;
|
||||
nums2 = _;
|
||||
}
|
||||
const nums1Set = new Set(nums1);
|
||||
const resSet = new Set();
|
||||
// for(const n of nums2) {
|
||||
// nums1Set.has(n) && resSet.add(n);
|
||||
// }
|
||||
// 循环 比 迭代器快
|
||||
for(let i = nums2.length - 1; i >= 0; i--) {
|
||||
nums1Set.has(nums2[i]) && resSet.add(nums2[i]);
|
||||
}
|
||||
return Array.from(resSet);
|
||||
};
|
||||
```
|
||||
|
||||
|
||||
## 相关题目
|
||||
|
||||
* 350.两个数组的交集 II
|
||||
|
||||
|
||||
-----------------------
|
||||
|
||||
@ -1,10 +1,10 @@
|
||||
<p align="center">
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/RsdcQ9umo09R6cfnwXZlrQ"><img src="https://img.shields.io/badge/PDF下载-代码随想录-blueviolet" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw"><img src="https://img.shields.io/badge/刷题-微信群-green" alt=""></a>
|
||||
<a href="https://img-blog.csdnimg.cn/20201210231711160.png"><img src="https://img.shields.io/badge/公众号-代码随想录-brightgreen" alt=""></a>
|
||||
<a href="https://space.bilibili.com/525438321"><img src="https://img.shields.io/badge/B站-代码随想录-orange" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
</p>
|
||||
<p align="center"><strong>欢迎大家参与本项目，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
<p align="center"><strong>欢迎大家<a href="https://mp.weixin.qq.com/s/tqCxrMEU-ajQumL1i8im9A">参与本项目</a>，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
|
||||
|
||||
> 本周讲解了[贪心理论基础](https://mp.weixin.qq.com/s/O935TaoHE9Eexwe_vSbRAg)，以及第一道贪心的题目：[贪心算法：分发饼干](https://mp.weixin.qq.com/s/YSuLIAYyRGlyxbp9BNC1uw)，可能会给大家一种贪心算法比较简单的错觉，好了，接下来几天的题目难度要上来了，哈哈。
|
||||
|
||||
@ -1,10 +1,10 @@
|
||||
<p align="center">
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/RsdcQ9umo09R6cfnwXZlrQ"><img src="https://img.shields.io/badge/PDF下载-代码随想录-blueviolet" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw"><img src="https://img.shields.io/badge/刷题-微信群-green" alt=""></a>
|
||||
<a href="https://img-blog.csdnimg.cn/20201210231711160.png"><img src="https://img.shields.io/badge/公众号-代码随想录-brightgreen" alt=""></a>
|
||||
<a href="https://space.bilibili.com/525438321"><img src="https://img.shields.io/badge/B站-代码随想录-orange" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
</p>
|
||||
<p align="center"><strong>欢迎大家参与本项目，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
<p align="center"><strong>欢迎大家<a href="https://mp.weixin.qq.com/s/tqCxrMEU-ajQumL1i8im9A">参与本项目</a>，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
# 动态规划：Carl称它为排列总和！
|
||||
|
||||
## 377. 组合总和 Ⅳ
|
||||
@ -191,4 +191,4 @@ Go：
|
||||
* 作者微信：[程序员Carl](https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw)
|
||||
* B站视频：[代码随想录](https://space.bilibili.com/525438321)
|
||||
* 知识星球：[代码随想录](https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ)
|
||||
<div align="center"><img src=../pics/公众号.png width=450 alt=> </img></div>
|
||||
<div align="center"><img src=../pics/公众号.png width=450 alt=> </img></div>
|
||||
|
||||
@ -1,10 +1,10 @@
|
||||
<p align="center">
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/RsdcQ9umo09R6cfnwXZlrQ"><img src="https://img.shields.io/badge/PDF下载-代码随想录-blueviolet" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw"><img src="https://img.shields.io/badge/刷题-微信群-green" alt=""></a>
|
||||
<a href="https://img-blog.csdnimg.cn/20201210231711160.png"><img src="https://img.shields.io/badge/公众号-代码随想录-brightgreen" alt=""></a>
|
||||
<a href="https://space.bilibili.com/525438321"><img src="https://img.shields.io/badge/B站-代码随想录-orange" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
</p>
|
||||
<p align="center"><strong>欢迎大家参与本项目，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
<p align="center"><strong>欢迎大家<a href="https://mp.weixin.qq.com/s/tqCxrMEU-ajQumL1i8im9A">参与本项目</a>，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
|
||||
|
||||
|
||||
@ -26,7 +26,7 @@ canConstruct("a", "b") -> false
|
||||
canConstruct("aa", "ab") -> false
|
||||
canConstruct("aa", "aab") -> true
|
||||
|
||||
# 思路
|
||||
## 思路
|
||||
|
||||
这道题目和[242.有效的字母异位词](https://mp.weixin.qq.com/s/vM6OszkM6L1Mx2Ralm9Dig)很像，[242.有效的字母异位词](https://mp.weixin.qq.com/s/vM6OszkM6L1Mx2Ralm9Dig)相当于求 字符串a 和 字符串b 是否可以相互组成 ，而这道题目是求 字符串a能否组成字符串b，而不用管字符串b 能不能组成字符串a。
|
||||
|
||||
@ -36,7 +36,7 @@ canConstruct("aa", "aab") -> true
|
||||
|
||||
* 第二点 “你可以假设两个字符串均只含有小写字母。” *说明只有小写字母*，这一点很重要
|
||||
|
||||
# 暴力解法
|
||||
## 暴力解法
|
||||
|
||||
那么第一个思路其实就是暴力枚举了，两层for循环，不断去寻找，代码如下：
|
||||
|
||||
@ -67,7 +67,7 @@ public:
|
||||
这里时间复杂度是比较高的，而且里面还有一个字符串删除也就是erase的操作，也是费时的，当然这段代码也可以过这道题。
|
||||
|
||||
|
||||
# 哈希解法
|
||||
## 哈希解法
|
||||
|
||||
因为题目所只有小写字母，那可以采用空间换取时间的哈希策略， 用一个长度为26的数组还记录magazine里字母出现的次数。
|
||||
|
||||
@ -105,8 +105,6 @@ public:
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
## 其他语言版本
|
||||
|
||||
|
||||
@ -138,10 +136,59 @@ class Solution {
|
||||
```
|
||||
|
||||
Python：
|
||||
|
||||
```py
|
||||
class Solution(object):
|
||||
def canConstruct(self, ransomNote, magazine):
|
||||
"""
|
||||
:type ransomNote: str
|
||||
:type magazine: str
|
||||
:rtype: bool
|
||||
"""
|
||||
|
||||
# use a dict to store the number of letter occurance in ransomNote
|
||||
hashmap = dict()
|
||||
for s in ransomNote:
|
||||
if s in hashmap:
|
||||
hashmap[s] += 1
|
||||
else:
|
||||
hashmap[s] = 1
|
||||
|
||||
# check if the letter we need can be found in magazine
|
||||
for l in magazine:
|
||||
if l in hashmap:
|
||||
hashmap[l] -= 1
|
||||
|
||||
for key in hashmap:
|
||||
if hashmap[key] > 0:
|
||||
return False
|
||||
|
||||
return True
|
||||
```
|
||||
|
||||
Go：
|
||||
|
||||
javaScript:
|
||||
|
||||
```js
|
||||
/**
|
||||
* @param {string} ransomNote
|
||||
* @param {string} magazine
|
||||
* @return {boolean}
|
||||
*/
|
||||
var canConstruct = function(ransomNote, magazine) {
|
||||
const strArr = new Array(26).fill(0),
|
||||
base = "a".charCodeAt();
|
||||
for(const s of magazine) {
|
||||
strArr[s.charCodeAt() - base]++;
|
||||
}
|
||||
for(const s of ransomNote) {
|
||||
const index = s.charCodeAt() - base;
|
||||
if(!strArr[index]) return false;
|
||||
strArr[index]--;
|
||||
}
|
||||
return true;
|
||||
};
|
||||
```
|
||||
|
||||
|
||||
|
||||
|
||||
@ -1,10 +1,10 @@
|
||||
<p align="center">
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/RsdcQ9umo09R6cfnwXZlrQ"><img src="https://img.shields.io/badge/PDF下载-代码随想录-blueviolet" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw"><img src="https://img.shields.io/badge/刷题-微信群-green" alt=""></a>
|
||||
<a href="https://img-blog.csdnimg.cn/20201210231711160.png"><img src="https://img.shields.io/badge/公众号-代码随想录-brightgreen" alt=""></a>
|
||||
<a href="https://space.bilibili.com/525438321"><img src="https://img.shields.io/badge/B站-代码随想录-orange" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
</p>
|
||||
<p align="center"><strong>欢迎大家参与本项目，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
<p align="center"><strong>欢迎大家<a href="https://mp.weixin.qq.com/s/tqCxrMEU-ajQumL1i8im9A">参与本项目</a>，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
|
||||
|
||||
## 392.判断子序列
|
||||
|
||||
@ -1,10 +1,10 @@
|
||||
<p align="center">
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/RsdcQ9umo09R6cfnwXZlrQ"><img src="https://img.shields.io/badge/PDF下载-代码随想录-blueviolet" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw"><img src="https://img.shields.io/badge/刷题-微信群-green" alt=""></a>
|
||||
<a href="https://img-blog.csdnimg.cn/20201210231711160.png"><img src="https://img.shields.io/badge/公众号-代码随想录-brightgreen" alt=""></a>
|
||||
<a href="https://space.bilibili.com/525438321"><img src="https://img.shields.io/badge/B站-代码随想录-orange" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
</p>
|
||||
<p align="center"><strong>欢迎大家参与本项目，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
<p align="center"><strong>欢迎大家<a href="https://mp.weixin.qq.com/s/tqCxrMEU-ajQumL1i8im9A">参与本项目</a>，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
|
||||
|
||||
## 404.左叶子之和
|
||||
@ -205,17 +205,34 @@ class Solution {
|
||||
|
||||
|
||||
Python：
|
||||
|
||||
|
||||
```Python
|
||||
**递归**
|
||||
# Definition for a binary tree node.
|
||||
# class TreeNode:
|
||||
# def __init__(self, val=0, left=None, right=None):
|
||||
# self.val = val
|
||||
# self.left = left
|
||||
# self.right = right
|
||||
class Solution:
|
||||
def sumOfLeftLeaves(self, root: TreeNode) -> int:
|
||||
self.res=0
|
||||
def areleftleaves(root):
|
||||
if not root:return
|
||||
if root.left and (not root.left.left) and (not root.left.right):self.res+=root.left.val
|
||||
areleftleaves(root.left)
|
||||
areleftleaves(root.right)
|
||||
areleftleaves(root)
|
||||
return self.res
|
||||
```
|
||||
Go：
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
-----------------------
|
||||
* 作者微信：[程序员Carl](https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw)
|
||||
* B站视频：[代码随想录](https://space.bilibili.com/525438321)
|
||||
* 知识星球：[代码随想录](https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ)
|
||||
|
||||
<div align="center"><img src=../pics/公众号.png width=450 alt=> </img></div>
|
||||
|
||||
|
||||
@ -1,10 +1,10 @@
|
||||
<p align="center">
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/RsdcQ9umo09R6cfnwXZlrQ"><img src="https://img.shields.io/badge/PDF下载-代码随想录-blueviolet" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw"><img src="https://img.shields.io/badge/刷题-微信群-green" alt=""></a>
|
||||
<a href="https://img-blog.csdnimg.cn/20201210231711160.png"><img src="https://img.shields.io/badge/公众号-代码随想录-brightgreen" alt=""></a>
|
||||
<a href="https://space.bilibili.com/525438321"><img src="https://img.shields.io/badge/B站-代码随想录-orange" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
</p>
|
||||
<p align="center"><strong>欢迎大家参与本项目，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
<p align="center"><strong>欢迎大家<a href="https://mp.weixin.qq.com/s/tqCxrMEU-ajQumL1i8im9A">参与本项目</a>，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
|
||||
|
||||
## 406.根据身高重建队列
|
||||
@ -211,7 +211,18 @@ class Solution {
|
||||
```
|
||||
|
||||
Python：
|
||||
|
||||
```python
|
||||
class Solution:
|
||||
def reconstructQueue(self, people: List[List[int]]) -> List[List[int]]:
|
||||
people.sort(key=lambda x: (x[0], -x[1]), reverse=True)
|
||||
que = []
|
||||
for p in people:
|
||||
if p[1] > len(que):
|
||||
que.append(p)
|
||||
else:
|
||||
que.insert(p[1], p)
|
||||
return que
|
||||
```
|
||||
|
||||
Go：
|
||||
|
||||
@ -222,4 +233,4 @@ Go：
|
||||
* 作者微信：[程序员Carl](https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw)
|
||||
* B站视频：[代码随想录](https://space.bilibili.com/525438321)
|
||||
* 知识星球：[代码随想录](https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ)
|
||||
<div align="center"><img src=../pics/公众号.png width=450 alt=> </img></div>
|
||||
<div align="center"><img src=../pics/公众号.png width=450 alt=> </img></div>
|
||||
|
||||
@ -1,10 +1,10 @@
|
||||
<p align="center">
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/RsdcQ9umo09R6cfnwXZlrQ"><img src="https://img.shields.io/badge/PDF下载-代码随想录-blueviolet" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw"><img src="https://img.shields.io/badge/刷题-微信群-green" alt=""></a>
|
||||
<a href="https://img-blog.csdnimg.cn/20201210231711160.png"><img src="https://img.shields.io/badge/公众号-代码随想录-brightgreen" alt=""></a>
|
||||
<a href="https://space.bilibili.com/525438321"><img src="https://img.shields.io/badge/B站-代码随想录-orange" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
</p>
|
||||
<p align="center"><strong>欢迎大家参与本项目，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
<p align="center"><strong>欢迎大家<a href="https://mp.weixin.qq.com/s/tqCxrMEU-ajQumL1i8im9A">参与本项目</a>，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
# 动态规划：分割等和子集可以用01背包！
|
||||
|
||||
## 416. 分割等和子集
|
||||
|
||||
@ -1,10 +1,10 @@
|
||||
<p align="center">
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/RsdcQ9umo09R6cfnwXZlrQ"><img src="https://img.shields.io/badge/PDF下载-代码随想录-blueviolet" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw"><img src="https://img.shields.io/badge/刷题-微信群-green" alt=""></a>
|
||||
<a href="https://img-blog.csdnimg.cn/20201210231711160.png"><img src="https://img.shields.io/badge/公众号-代码随想录-brightgreen" alt=""></a>
|
||||
<a href="https://space.bilibili.com/525438321"><img src="https://img.shields.io/badge/B站-代码随想录-orange" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
</p>
|
||||
<p align="center"><strong>欢迎大家参与本项目，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
<p align="center"><strong>欢迎大家<a href="https://mp.weixin.qq.com/s/tqCxrMEU-ajQumL1i8im9A">参与本项目</a>，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
|
||||
|
||||
## 435. 无重叠区间
|
||||
@ -212,7 +212,19 @@ class Solution {
|
||||
```
|
||||
|
||||
Python：
|
||||
|
||||
```python
|
||||
class Solution:
|
||||
def eraseOverlapIntervals(self, intervals: List[List[int]]) -> int:
|
||||
if len(intervals) == 0: return 0
|
||||
intervals.sort(key=lambda x: x[1])
|
||||
count = 1 # 记录非交叉区间的个数
|
||||
end = intervals[0][1] # 记录区间分割点
|
||||
for i in range(1, len(intervals)):
|
||||
if end <= intervals[i][0]:
|
||||
count += 1
|
||||
end = intervals[i][1]
|
||||
return len(intervals) - count
|
||||
```
|
||||
|
||||
Go：
|
||||
|
||||
@ -223,4 +235,4 @@ Go：
|
||||
* 作者微信：[程序员Carl](https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw)
|
||||
* B站视频：[代码随想录](https://space.bilibili.com/525438321)
|
||||
* 知识星球：[代码随想录](https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ)
|
||||
<div align="center"><img src=../pics/公众号.png width=450 alt=> </img></div>
|
||||
<div align="center"><img src=../pics/公众号.png width=450 alt=> </img></div>
|
||||
|
||||
@ -1,10 +1,10 @@
|
||||
<p align="center">
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/RsdcQ9umo09R6cfnwXZlrQ"><img src="https://img.shields.io/badge/PDF下载-代码随想录-blueviolet" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw"><img src="https://img.shields.io/badge/刷题-微信群-green" alt=""></a>
|
||||
<a href="https://img-blog.csdnimg.cn/20201210231711160.png"><img src="https://img.shields.io/badge/公众号-代码随想录-brightgreen" alt=""></a>
|
||||
<a href="https://space.bilibili.com/525438321"><img src="https://img.shields.io/badge/B站-代码随想录-orange" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
</p>
|
||||
<p align="center"><strong>欢迎大家参与本项目，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
<p align="center"><strong>欢迎大家<a href="https://mp.weixin.qq.com/s/tqCxrMEU-ajQumL1i8im9A">参与本项目</a>，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
|
||||
|
||||
> 二叉搜索树删除节点就涉及到结构调整了
|
||||
@ -281,7 +281,43 @@ class Solution {
|
||||
```
|
||||
|
||||
Python：
|
||||
|
||||
```python
|
||||
# Definition for a binary tree node.
|
||||
# class TreeNode:
|
||||
# def __init__(self, val=0, left=None, right=None):
|
||||
# self.val = val
|
||||
# self.left = left
|
||||
# self.right = right
|
||||
class Solution:
|
||||
def deleteNode(self, root: TreeNode, key: int) -> TreeNode:
|
||||
if not root: return root #第一种情况：没找到删除的节点，遍历到空节点直接返回了
|
||||
if root.val == key:
|
||||
if not root.left and not root.right: #第二种情况：左右孩子都为空（叶子节点），直接删除节点， 返回NULL为根节点
|
||||
del root
|
||||
return None
|
||||
if not root.left and root.right: #第三种情况：其左孩子为空，右孩子不为空，删除节点，右孩子补位 ，返回右孩子为根节点
|
||||
tmp = root
|
||||
root = root.right
|
||||
del tmp
|
||||
return root
|
||||
if root.left and not root.right: #第四种情况：其右孩子为空，左孩子不为空，删除节点，左孩子补位，返回左孩子为根节点
|
||||
tmp = root
|
||||
root = root.left
|
||||
del tmp
|
||||
return root
|
||||
else: #第五种情况：左右孩子节点都不为空，则将删除节点的左子树放到删除节点的右子树的最左面节点的左孩子的位置
|
||||
v = root.right
|
||||
while v.left:
|
||||
v = v.left
|
||||
v.left = root.left
|
||||
tmp = root
|
||||
root = root.right
|
||||
del tmp
|
||||
return root
|
||||
if root.val > key: root.left = self.deleteNode(root.left,key) #左递归
|
||||
if root.val < key: root.right = self.deleteNode(root.right,key) #右递归
|
||||
return root
|
||||
```
|
||||
|
||||
Go：
|
||||
```Go
|
||||
@ -330,4 +366,4 @@ func deleteNode1(root *TreeNode)*TreeNode{
|
||||
* 作者微信：[程序员Carl](https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw)
|
||||
* B站视频：[代码随想录](https://space.bilibili.com/525438321)
|
||||
* 知识星球：[代码随想录](https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ)
|
||||
<div align="center"><img src=../pics/公众号.png width=450 alt=> </img></div>
|
||||
<div align="center"><img src=../pics/公众号.png width=450 alt=> </img></div>
|
||||
|
||||
@ -1,10 +1,10 @@
|
||||
<p align="center">
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/RsdcQ9umo09R6cfnwXZlrQ"><img src="https://img.shields.io/badge/PDF下载-代码随想录-blueviolet" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw"><img src="https://img.shields.io/badge/刷题-微信群-green" alt=""></a>
|
||||
<a href="https://img-blog.csdnimg.cn/20201210231711160.png"><img src="https://img.shields.io/badge/公众号-代码随想录-brightgreen" alt=""></a>
|
||||
<a href="https://space.bilibili.com/525438321"><img src="https://img.shields.io/badge/B站-代码随想录-orange" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
</p>
|
||||
<p align="center"><strong>欢迎大家参与本项目，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
<p align="center"><strong>欢迎大家<a href="https://mp.weixin.qq.com/s/tqCxrMEU-ajQumL1i8im9A">参与本项目</a>，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
|
||||
|
||||
## 452. 用最少数量的箭引爆气球
|
||||
@ -70,7 +70,7 @@
|
||||
|
||||
其实都可以！只不过对应的遍历顺序不同，我就按照气球的起始位置排序了。
|
||||
|
||||
既然按照其实位置排序，那么就从前向后遍历气球数组，靠左尽可能让气球重复。
|
||||
既然按照起始位置排序，那么就从前向后遍历气球数组，靠左尽可能让气球重复。
|
||||
|
||||
从前向后遍历遇到重叠的气球了怎么办？
|
||||
|
||||
@ -167,7 +167,19 @@ class Solution {
|
||||
```
|
||||
|
||||
Python：
|
||||
|
||||
```python
|
||||
class Solution:
|
||||
def findMinArrowShots(self, points: List[List[int]]) -> int:
|
||||
if len(points) == 0: return 0
|
||||
points.sort(key=lambda x: x[0])
|
||||
result = 1
|
||||
for i in range(1, len(points)):
|
||||
if points[i][0] > points[i - 1][1]: # 气球i和气球i-1不挨着，注意这里不是>=
|
||||
result += 1
|
||||
else:
|
||||
points[i][1] = min(points[i - 1][1], points[i][1]) # 更新重叠气球最小右边界
|
||||
return result
|
||||
```
|
||||
|
||||
Go：
|
||||
|
||||
@ -178,4 +190,4 @@ Go：
|
||||
* 作者微信：[程序员Carl](https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw)
|
||||
* B站视频：[代码随想录](https://space.bilibili.com/525438321)
|
||||
* 知识星球：[代码随想录](https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ)
|
||||
<div align="center"><img src=../pics/公众号.png width=450 alt=> </img></div>
|
||||
<div align="center"><img src=../pics/公众号.png width=450 alt=> </img></div>
|
||||
|
||||
@ -1,10 +1,10 @@
|
||||
<p align="center">
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/RsdcQ9umo09R6cfnwXZlrQ"><img src="https://img.shields.io/badge/PDF下载-代码随想录-blueviolet" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw"><img src="https://img.shields.io/badge/刷题-微信群-green" alt=""></a>
|
||||
<a href="https://img-blog.csdnimg.cn/20201210231711160.png"><img src="https://img.shields.io/badge/公众号-代码随想录-brightgreen" alt=""></a>
|
||||
<a href="https://space.bilibili.com/525438321"><img src="https://img.shields.io/badge/B站-代码随想录-orange" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
</p>
|
||||
<p align="center"><strong>欢迎大家参与本项目，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
<p align="center"><strong>欢迎大家<a href="https://mp.weixin.qq.com/s/tqCxrMEU-ajQumL1i8im9A">参与本项目</a>，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
|
||||
|
||||
> 需要哈希的地方都能找到map的身影
|
||||
@ -121,9 +121,72 @@ class Solution {
|
||||
|
||||
Python：
|
||||
|
||||
```
|
||||
class Solution(object):
|
||||
def fourSumCount(self, nums1, nums2, nums3, nums4):
|
||||
"""
|
||||
:type nums1: List[int]
|
||||
:type nums2: List[int]
|
||||
:type nums3: List[int]
|
||||
:type nums4: List[int]
|
||||
:rtype: int
|
||||
"""
|
||||
# use a dict to store the elements in nums1 and nums2 and their sum
|
||||
hashmap = dict()
|
||||
for n1 in nums1:
|
||||
for n2 in nums2:
|
||||
if n1 + n2 in hashmap:
|
||||
hashmap[n1+n2] += 1
|
||||
else:
|
||||
hashmap[n1+n2] = 1
|
||||
|
||||
# if the -(a+b) exists in nums3 and nums4, we shall add the count
|
||||
count = 0
|
||||
for n3 in nums3:
|
||||
for n4 in nums4:
|
||||
key = - n3 - n4
|
||||
if key in hashmap:
|
||||
count += hashmap[key]
|
||||
return count
|
||||
|
||||
|
||||
```
|
||||
|
||||
|
||||
Go：
|
||||
|
||||
javaScript:
|
||||
|
||||
```js
|
||||
/**
|
||||
* @param {number[]} nums1
|
||||
* @param {number[]} nums2
|
||||
* @param {number[]} nums3
|
||||
* @param {number[]} nums4
|
||||
* @return {number}
|
||||
*/
|
||||
var fourSumCount = function(nums1, nums2, nums3, nums4) {
|
||||
const twoSumMap = new Map();
|
||||
let count = 0;
|
||||
|
||||
for(const n1 of nums1) {
|
||||
for(const n2 of nums2) {
|
||||
const sum = n1 + n2;
|
||||
twoSumMap.set(sum, (twoSumMap.get(sum) || 0) + 1)
|
||||
}
|
||||
}
|
||||
|
||||
for(const n3 of nums3) {
|
||||
for(const n4 of nums4) {
|
||||
const sum = n3 + n4;
|
||||
count += (twoSumMap.get(0 - sum) || 0)
|
||||
}
|
||||
}
|
||||
|
||||
return count;
|
||||
};
|
||||
```
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
@ -1,10 +1,10 @@
|
||||
<p align="center">
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/RsdcQ9umo09R6cfnwXZlrQ"><img src="https://img.shields.io/badge/PDF下载-代码随想录-blueviolet" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw"><img src="https://img.shields.io/badge/刷题-微信群-green" alt=""></a>
|
||||
<a href="https://img-blog.csdnimg.cn/20201210231711160.png"><img src="https://img.shields.io/badge/公众号-代码随想录-brightgreen" alt=""></a>
|
||||
<a href="https://space.bilibili.com/525438321"><img src="https://img.shields.io/badge/B站-代码随想录-orange" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
</p>
|
||||
<p align="center"><strong>欢迎大家参与本项目，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
<p align="center"><strong>欢迎大家<a href="https://mp.weixin.qq.com/s/tqCxrMEU-ajQumL1i8im9A">参与本项目</a>，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
|
||||
|
||||
## 455.分发饼干
|
||||
@ -145,4 +145,4 @@ Go：
|
||||
* 作者微信：[程序员Carl](https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw)
|
||||
* B站视频：[代码随想录](https://space.bilibili.com/525438321)
|
||||
* 知识星球：[代码随想录](https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ)
|
||||
<div align="center"><img src=../pics/公众号.png width=450 alt=> </img></div>
|
||||
<div align="center"><img src=../pics/公众号.png width=450 alt=> </img></div>
|
||||
|
||||
@ -1,10 +1,10 @@
|
||||
<p align="center">
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/RsdcQ9umo09R6cfnwXZlrQ"><img src="https://img.shields.io/badge/PDF下载-代码随想录-blueviolet" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw"><img src="https://img.shields.io/badge/刷题-微信群-green" alt=""></a>
|
||||
<a href="https://img-blog.csdnimg.cn/20201210231711160.png"><img src="https://img.shields.io/badge/公众号-代码随想录-brightgreen" alt=""></a>
|
||||
<a href="https://space.bilibili.com/525438321"><img src="https://img.shields.io/badge/B站-代码随想录-orange" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
</p>
|
||||
<p align="center"><strong>欢迎大家参与本项目，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
<p align="center"><strong>欢迎大家<a href="https://mp.weixin.qq.com/s/tqCxrMEU-ajQumL1i8im9A">参与本项目</a>，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
|
||||
|
||||
|
||||
@ -149,9 +149,38 @@ public:
|
||||
|
||||
## 其他语言版本
|
||||
|
||||
|
||||
Java：
|
||||
|
||||
```java
|
||||
class Solution {
|
||||
public boolean repeatedSubstringPattern(String s) {
|
||||
if (s.equals("")) return false;
|
||||
|
||||
int len = s.length();
|
||||
// 原串加个空格(哨兵)，使下标从1开始，这样j从0开始，也不用初始化了
|
||||
s = " " + s;
|
||||
char[] chars = s.toCharArray();
|
||||
int[] next = new int[len + 1];
|
||||
|
||||
// 构造 next 数组过程，j从0开始(空格)，i从2开始
|
||||
for (int i = 2, j = 0; i <= len; i++) {
|
||||
// 匹配不成功，j回到前一位置 next 数组所对应的值
|
||||
while (j > 0 && chars[i] != chars[j + 1]) j = next[j];
|
||||
// 匹配成功，j往后移
|
||||
if (chars[i] == chars[j + 1]) j++;
|
||||
// 更新 next 数组的值
|
||||
next[i] = j;
|
||||
}
|
||||
|
||||
// 最后判断是否是重复的子字符串，这里 next[len] 即代表next数组末尾的值
|
||||
if (next[len] > 0 && len % (len - next[len]) == 0) {
|
||||
return true;
|
||||
}
|
||||
return false;
|
||||
}
|
||||
}
|
||||
```
|
||||
|
||||
|
||||
Python：
|
||||
|
||||
|
||||
@ -1,10 +1,10 @@
|
||||
<p align="center">
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/RsdcQ9umo09R6cfnwXZlrQ"><img src="https://img.shields.io/badge/PDF下载-代码随想录-blueviolet" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw"><img src="https://img.shields.io/badge/刷题-微信群-green" alt=""></a>
|
||||
<a href="https://img-blog.csdnimg.cn/20201210231711160.png"><img src="https://img.shields.io/badge/公众号-代码随想录-brightgreen" alt=""></a>
|
||||
<a href="https://space.bilibili.com/525438321"><img src="https://img.shields.io/badge/B站-代码随想录-orange" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
</p>
|
||||
<p align="center"><strong>欢迎大家参与本项目，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
<p align="center"><strong>欢迎大家<a href="https://mp.weixin.qq.com/s/tqCxrMEU-ajQumL1i8im9A">参与本项目</a>，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
# 动态规划：一和零！
|
||||
|
||||
## 474.一和零
|
||||
|
||||
@ -1,10 +1,10 @@
|
||||
<p align="center">
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/RsdcQ9umo09R6cfnwXZlrQ"><img src="https://img.shields.io/badge/PDF下载-代码随想录-blueviolet" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw"><img src="https://img.shields.io/badge/刷题-微信群-green" alt=""></a>
|
||||
<a href="https://img-blog.csdnimg.cn/20201210231711160.png"><img src="https://img.shields.io/badge/公众号-代码随想录-brightgreen" alt=""></a>
|
||||
<a href="https://space.bilibili.com/525438321"><img src="https://img.shields.io/badge/B站-代码随想录-orange" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
</p>
|
||||
<p align="center"><strong>欢迎大家参与本项目，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
<p align="center"><strong>欢迎大家<a href="https://mp.weixin.qq.com/s/tqCxrMEU-ajQumL1i8im9A">参与本项目</a>，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
|
||||
|
||||
> 和子集问题有点像，但又处处是陷阱
|
||||
@ -268,4 +268,4 @@ var findSubsequences = function(nums) {
|
||||
* 作者微信：[程序员Carl](https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw)
|
||||
* B站视频：[代码随想录](https://space.bilibili.com/525438321)
|
||||
* 知识星球：[代码随想录](https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ)
|
||||
<div align="center"><img src=../pics/公众号.png width=450 alt=> </img></div>
|
||||
<div align="center"><img src=../pics/公众号.png width=450 alt=> </img></div>
|
||||
|
||||
@ -1,10 +1,10 @@
|
||||
<p align="center">
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/RsdcQ9umo09R6cfnwXZlrQ"><img src="https://img.shields.io/badge/PDF下载-代码随想录-blueviolet" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw"><img src="https://img.shields.io/badge/刷题-微信群-green" alt=""></a>
|
||||
<a href="https://img-blog.csdnimg.cn/20201210231711160.png"><img src="https://img.shields.io/badge/公众号-代码随想录-brightgreen" alt=""></a>
|
||||
<a href="https://space.bilibili.com/525438321"><img src="https://img.shields.io/badge/B站-代码随想录-orange" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
</p>
|
||||
<p align="center"><strong>欢迎大家参与本项目，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
<p align="center"><strong>欢迎大家<a href="https://mp.weixin.qq.com/s/tqCxrMEU-ajQumL1i8im9A">参与本项目</a>，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
# 动态规划：目标和！
|
||||
|
||||
## 494. 目标和
|
||||
@ -225,7 +225,7 @@ public:
|
||||
|
||||
是的，如果仅仅是求个数的话，就可以用dp，但[回溯算法：39. 组合总和](https://mp.weixin.qq.com/s/FLg8G6EjVcxBjwCbzpACPw)要求的是把所有组合列出来，还是要使用回溯法爆搜的。
|
||||
|
||||
本地还是有点难度，大家也可以记住，在求装满背包有几种方法的情况下，递推公式一般为：
|
||||
本题还是有点难度，大家也可以记住，在求装满背包有几种方法的情况下，递推公式一般为：
|
||||
|
||||
```
|
||||
dp[j] += dp[j - nums[i]];
|
||||
@ -272,4 +272,4 @@ Go：
|
||||
* 作者微信：[程序员Carl](https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw)
|
||||
* B站视频：[代码随想录](https://space.bilibili.com/525438321)
|
||||
* 知识星球：[代码随想录](https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ)
|
||||
<div align="center"><img src=../pics/公众号.png width=450 alt=> </img></div>
|
||||
<div align="center"><img src=../pics/公众号.png width=450 alt=> </img></div>
|
||||
|
||||
@ -1,10 +1,10 @@
|
||||
<p align="center">
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/RsdcQ9umo09R6cfnwXZlrQ"><img src="https://img.shields.io/badge/PDF下载-代码随想录-blueviolet" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw"><img src="https://img.shields.io/badge/刷题-微信群-green" alt=""></a>
|
||||
<a href="https://img-blog.csdnimg.cn/20201210231711160.png"><img src="https://img.shields.io/badge/公众号-代码随想录-brightgreen" alt=""></a>
|
||||
<a href="https://space.bilibili.com/525438321"><img src="https://img.shields.io/badge/B站-代码随想录-orange" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
</p>
|
||||
<p align="center"><strong>欢迎大家参与本项目，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
<p align="center"><strong>欢迎大家<a href="https://mp.weixin.qq.com/s/tqCxrMEU-ajQumL1i8im9A">参与本项目</a>，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
|
||||
|
||||
> 二叉树上应该怎么求，二叉搜索树上又应该怎么求？
|
||||
@ -394,8 +394,39 @@ class Solution {
|
||||
```
|
||||
|
||||
Python：
|
||||
|
||||
|
||||
```python
|
||||
# Definition for a binary tree node.
|
||||
# class TreeNode:
|
||||
# def __init__(self, val=0, left=None, right=None):
|
||||
# self.val = val
|
||||
# self.left = left
|
||||
# self.right = right
|
||||
//递归法
|
||||
class Solution:
|
||||
def findMode(self, root: TreeNode) -> List[int]:
|
||||
if not root: return
|
||||
self.pre = root
|
||||
self.count = 0 //统计频率
|
||||
self.countMax = 0 //最大频率
|
||||
self.res = []
|
||||
def findNumber(root):
|
||||
if not root: return None // 第一个节点
|
||||
findNumber(root.left) //左
|
||||
if self.pre.val == root.val: //中: 与前一个节点数值相同
|
||||
self.count += 1
|
||||
else: // 与前一个节点数值不同
|
||||
self.pre = root
|
||||
self.count = 1
|
||||
if self.count > self.countMax: // 如果计数大于最大值频率
|
||||
self.countMax = self.count // 更新最大频率
|
||||
self.res = [root.val] //更新res
|
||||
elif self.count == self.countMax: // 如果和最大值相同，放进res中
|
||||
self.res.append(root.val)
|
||||
findNumber(root.right) //右
|
||||
return
|
||||
findNumber(root)
|
||||
return self.res
|
||||
```
|
||||
Go：
|
||||
|
||||
|
||||
@ -405,4 +436,4 @@ Go：
|
||||
* 作者微信：[程序员Carl](https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw)
|
||||
* B站视频：[代码随想录](https://space.bilibili.com/525438321)
|
||||
* 知识星球：[代码随想录](https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ)
|
||||
<div align="center"><img src=../pics/公众号.png width=450 alt=> </img></div>
|
||||
<div align="center"><img src=../pics/公众号.png width=450 alt=> </img></div>
|
||||
|
||||
@ -1,10 +1,10 @@
|
||||
<p align="center">
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/RsdcQ9umo09R6cfnwXZlrQ"><img src="https://img.shields.io/badge/PDF下载-代码随想录-blueviolet" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw"><img src="https://img.shields.io/badge/刷题-微信群-green" alt=""></a>
|
||||
<a href="https://img-blog.csdnimg.cn/20201210231711160.png"><img src="https://img.shields.io/badge/公众号-代码随想录-brightgreen" alt=""></a>
|
||||
<a href="https://space.bilibili.com/525438321"><img src="https://img.shields.io/badge/B站-代码随想录-orange" alt=""></a>
|
||||
<a href="https://mp.weixin.qq.com/s/QVF6upVMSbgvZy8lHZS3CQ"><img src="https://img.shields.io/badge/知识星球-代码随想录-blue" alt=""></a>
|
||||
</p>
|
||||
<p align="center"><strong>欢迎大家参与本项目，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
<p align="center"><strong>欢迎大家<a href="https://mp.weixin.qq.com/s/tqCxrMEU-ajQumL1i8im9A">参与本项目</a>，贡献其他语言版本的代码，拥抱开源，让更多学习算法的小伙伴们收益！</strong></p>
|
||||
|
||||
## 509. 斐波那契数
|
||||
|
||||
@ -187,9 +187,39 @@ class Solution {
|
||||
```
|
||||
|
||||
Python：
|
||||
```python3
|
||||
class Solution:
|
||||
def fib(self, n: int) -> int:
|
||||
if n < 2:
|
||||
return n
|
||||
a, b, c = 0, 1, 0
|
||||
for i in range(1, n):
|
||||
c = a + b
|
||||
a, b = b, c
|
||||
return c
|
||||
|
||||
# 递归实现
|
||||
class Solution:
|
||||
def fib(self, n: int) -> int:
|
||||
if n < 2:
|
||||
return n
|
||||
return self.fib(n - 1) + self.fib(n - 2)
|
||||
```
|
||||
|
||||
Go：
|
||||
```Go
|
||||
func fib(n int) int {
|
||||
if n < 2 {
|
||||
return n
|
||||
}
|
||||
a, b, c := 0, 1, 0
|
||||
for i := 1; i < n; i++ {
|
||||
c = a + b
|
||||
a, b = b, c
|
||||
}
|
||||
return c
|
||||
}
|
||||
```
|
||||
|
||||
|
||||
|
||||
|
||||
Some files were not shown because too many files have changed in this diff Show More
Reference in New Issue
Block a user