From f035549e04458aa52b8d4c6843a7b6938a0cd9a6 Mon Sep 17 00:00:00 2001 From: jojoo15 <75017412+jojoo15@users.noreply.github.com> Date: Wed, 19 May 2021 15:40:05 +0200 Subject: [PATCH 01/47] =?UTF-8?q?=E6=B7=BB=E5=8A=A0=200501.=E4=BA=8C?= =?UTF-8?q?=E5=8F=89=E6=90=9C=E7=B4=A2=E6=A0=91=E4=B8=AD=E7=9A=84=E4=BC=97?= =?UTF-8?q?=E6=95=B0=20python=E7=89=88=E6=9C=AC?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- problems/0501.二叉搜索树中的众数.md | 37 ++++++++++++++++++-- 1 file changed, 34 insertions(+), 3 deletions(-) diff --git a/problems/0501.二叉搜索树中的众数.md b/problems/0501.二叉搜索树中的众数.md index 385ce2f1..0ddd8b0c 100644 --- a/problems/0501.二叉搜索树中的众数.md +++ b/problems/0501.二叉搜索树中的众数.md @@ -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) -
\ No newline at end of file +
From 03964a1f78a47710b2406d9a4ec00d3d73f0fddd Mon Sep 17 00:00:00 2001 From: Powerstot <77142630+Powerstot@users.noreply.github.com> Date: Wed, 19 May 2021 22:26:03 +0800 Subject: [PATCH 02/47] =?UTF-8?q?=E4=BF=AE=E6=94=B91047.=E5=88=A0=E9=99=A4?= =?UTF-8?q?=E5=AD=97=E7=AC=A6=E4=B8=B2=E4=B8=AD=E7=9A=84=E6=89=80=E6=9C=89?= =?UTF-8?q?=E7=9B=B8=E9=82=BB=E9=87=8D=E5=A4=8D=E9=A1=B9=20Java=E7=89=88?= =?UTF-8?q?=E6=9C=AC?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 修改1047.删除字符串中的所有相邻重复项 Java版本 --- ...除字符串中的所有相邻重复项.md | 26 +++++++++++++++++++ 1 file changed, 26 insertions(+) diff --git a/problems/1047.删除字符串中的所有相邻重复项.md b/problems/1047.删除字符串中的所有相邻重复项.md index 607a4ccf..32a29c2a 100644 --- a/problems/1047.删除字符串中的所有相邻重复项.md +++ b/problems/1047.删除字符串中的所有相邻重复项.md @@ -122,6 +122,8 @@ public: Java： + +使用 Deque 作为堆栈 ```Java class Solution { public String removeDuplicates(String S) { @@ -144,6 +146,30 @@ class Solution { } } ``` +拿字符串直接作为栈，省去了栈还要转为字符串的操作。 +```Java +class Solution { + public String removeDuplicates(String s) { + // 将 res 当做栈 + StringBuffer res = new StringBuffer(); + // top为 res 的长度 + int top = -1; + for (int i = 0; i < s.length(); i++) { + char c = s.charAt(i); + // 当 top > 0,即栈中有字符时，当前字符如果和栈中字符相等，弹出栈顶字符，同时 top-- + if (top >= 0 && res.charAt(top) == c) { + res.deleteCharAt(top); + top--; + // 否则，将该字符 入栈，同时top++ + } else { + res.append(c); + top++; + } + } + return res.toString(); + } +} +``` Python： ```python3 From 8efc21f92d6485b52d7d24391da9d88090c5bd59 Mon Sep 17 00:00:00 2001 From: LiangDazhu <42199191+LiangDazhu@users.noreply.github.com> Date: Wed, 19 May 2021 23:23:38 +0800 Subject: [PATCH 03/47] =?UTF-8?q?Update=200452.=E7=94=A8=E6=9C=80=E5=B0=91?= =?UTF-8?q?=E6=95=B0=E9=87=8F=E7=9A=84=E7=AE=AD=E5=BC=95=E7=88=86=E6=B0=94?= =?UTF-8?q?=E7=90=83.md?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Added python version code --- .../0452.用最少数量的箭引爆气球.md | 18 +++++++++++++++--- 1 file changed, 15 insertions(+), 3 deletions(-) diff --git a/problems/0452.用最少数量的箭引爆气球.md b/problems/0452.用最少数量的箭引爆气球.md index f62fb153..45c94a01 100644 --- a/problems/0452.用最少数量的箭引爆气球.md +++ b/problems/0452.用最少数量的箭引爆气球.md @@ -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) -
\ No newline at end of file +
From ae6cd5a7ae35b4c1c838bbf967c2c27395591080 Mon Sep 17 00:00:00 2001 From: LiangDazhu <42199191+LiangDazhu@users.noreply.github.com> Date: Wed, 19 May 2021 23:51:59 +0800 Subject: [PATCH 04/47] =?UTF-8?q?Update=200435.=E6=97=A0=E9=87=8D=E5=8F=A0?= =?UTF-8?q?=E5=8C=BA=E9=97=B4.md?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Added python version code --- problems/0435.无重叠区间.md | 16 ++++++++++++++-- 1 file changed, 14 insertions(+), 2 deletions(-) diff --git a/problems/0435.无重叠区间.md b/problems/0435.无重叠区间.md index 4341f3b8..540a82e3 100644 --- a/problems/0435.无重叠区间.md +++ b/problems/0435.无重叠区间.md @@ -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) -
\ No newline at end of file +
From 5155c815ed5bfdc1004d50da41cfcc2f66837567 Mon Sep 17 00:00:00 2001 From: jojoo15 <75017412+jojoo15@users.noreply.github.com> Date: Thu, 20 May 2021 00:06:55 +0200 Subject: [PATCH 05/47] =?UTF-8?q?=E6=B7=BB=E5=8A=A0=200236.=20=E4=BA=8C?= =?UTF-8?q?=E5=8F=89=E6=A0=91=E7=9A=84=E6=9C=80=E8=BF=91=E5=85=AC=E5=85=B1?= =?UTF-8?q?=E7=A5=96=E5=85=88=20python=E7=89=88=E6=9C=AC?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit added python version of code --- .../0236.二叉树的最近公共祖先.md | 20 +++++++++++++++++-- 1 file changed, 18 insertions(+), 2 deletions(-) diff --git a/problems/0236.二叉树的最近公共祖先.md b/problems/0236.二叉树的最近公共祖先.md index 3233c6a1..a32c017e 100644 --- a/problems/0236.二叉树的最近公共祖先.md +++ b/problems/0236.二叉树的最近公共祖先.md @@ -263,8 +263,24 @@ 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 { From 15824a1c2b95cf3811a5cd478fb84a844a7ac35d Mon Sep 17 00:00:00 2001 From: fusunx <1102654482@qq.com> Date: Thu, 20 May 2021 08:02:34 +0800 Subject: [PATCH 06/47] =?UTF-8?q?0332.=E9=87=8D=E6=96=B0=E5=AE=89=E6=8E=92?= =?UTF-8?q?=E8=A1=8C=E7=A8=8B=20Javascript?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- problems/0332.重新安排行程.md | 43 +++++++++++++++++++++++++++++ 1 file changed, 43 insertions(+) diff --git a/problems/0332.重新安排行程.md b/problems/0332.重新安排行程.md index 756ecc86..0260a34b 100644 --- a/problems/0332.重新安排行程.md +++ b/problems/0332.重新安排行程.md @@ -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) From 30a39b71f503f57b4feb1020203d0af7d22de77c Mon Sep 17 00:00:00 2001 From: xll <18574553598@163.com> Date: Thu, 20 May 2021 13:10:26 +0800 Subject: [PATCH 07/47] =?UTF-8?q?=E4=BA=8C=E5=8F=89=E6=A0=91=E7=9A=84?= =?UTF-8?q?=E9=80=92=E5=BD=92=E9=81=8D=E5=8E=86JavaScript=E7=89=88?= =?UTF-8?q?=E6=9C=AC?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- problems/二叉树的递归遍历.md | 53 ++++++++++++++++++++++++++++ 1 file changed, 53 insertions(+) diff --git a/problems/二叉树的递归遍历.md b/problems/二叉树的递归遍历.md index 2d571294..e5279ec0 100644 --- a/problems/二叉树的递归遍历.md +++ b/problems/二叉树的递归遍历.md @@ -306,6 +306,59 @@ var postorderTraversal = function(root, res = []) { return res; }; ``` +Javascript版本： + +前序遍历： +```Javascript +var preorderTraversal = function(root) { + let res=[]; + const dfs=function(root){ + if(root===null)return ; + //先序遍历所以从父节点开始 + res.push(root.val); + //递归左子树 + dfs(root.left); + //递归右子树 + dfs(root.right); + } + //只使用一个参数 使用闭包进行存储结果 + dfs(root); + return res; +}; +``` +中序遍历 +```javascript +var inorderTraversal = function(root) { + let res=[]; + const dfs=function(root){ + if(root===null){ + return ; + } + dfs(root.left); + res.push(root.val); + dfs(root.right); + } + dfs(root); + return res; +}; +``` + +后序遍历 +```javascript +var postorderTraversal = function(root) { + let res=[]; + const dfs=function(root){ + if(root===null){ + return ; + } + dfs(root.left); + dfs(root.right); + res.push(root.val); + } + dfs(root); + return res; +}; +``` From ed557367383ab0df57e47074fcd751bcaba2308d Mon Sep 17 00:00:00 2001 From: reoaah Date: Thu, 20 May 2021 14:37:47 +0800 Subject: [PATCH 08/47] =?UTF-8?q?=E6=B7=BB=E5=8A=A00509.=E6=96=90=E6=B3=A2?= =?UTF-8?q?=E9=82=A3=E5=A5=91=E6=95=B0.md=20Go=E7=89=88=E6=9C=AC?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- problems/0509.斐波那契数.md | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/problems/0509.斐波那契数.md b/problems/0509.斐波那契数.md index 112c96f9..5afcd6b8 100644 --- a/problems/0509.斐波那契数.md +++ b/problems/0509.斐波那契数.md @@ -207,6 +207,19 @@ class Solution: ``` 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 +} +``` From 8c5c5c03c6e7d53385778ae8eee0876f71056080 Mon Sep 17 00:00:00 2001 From: "qingyi.liu" Date: Thu, 20 May 2021 14:50:56 +0800 Subject: [PATCH 09/47] =?UTF-8?q?=E6=B7=BB=E5=8A=A0=20704.=20=E4=BA=8C?= =?UTF-8?q?=E5=88=86=E6=9F=A5=E6=89=BE=20javaScript=E7=89=88=E6=9C=AC?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- problems/0704.二分查找.md | 37 +++++++++++++++++++++++++++++++++++ 1 file changed, 37 insertions(+) diff --git a/problems/0704.二分查找.md b/problems/0704.二分查找.md index 76d4a2af..c97fd36e 100644 --- a/problems/0704.二分查找.md +++ b/problems/0704.二分查找.md @@ -254,6 +254,43 @@ func search(nums []int, target int) int { } ``` +javaScript + +```js + +// （版本一）左闭右闭区间 + +var search = function(nums, target) { + let l = 0, r = nums.length - 1; + // 区间 [l, r] + while(l <= r) { + let mid = (l + r) >> 1; + if(nums[mid] === target) return mid; + let isSmall = nums[mid] < target; + l = isSmall ? mid + 1 : l; + r = isSmall ? r : mid - 1; + } + return -1; +}; + +// （版本二）左闭右开区间 + +var search = function(nums, target) { + let l = 0, r = nums.length; + // 区间 [l, r） + while(l < r) { + let mid = (l + r) >> 1; + if(nums[mid] === target) return mid; + let isSmall = nums[mid] < target; + l = isSmall ? mid + 1 : l; + // 所以 mid 不会被取到 + r = isSmall ? r : mid; + } + return -1; +}; + +``` + From 9a919464bf7e70e77e97168e29591b449bdd5c30 Mon Sep 17 00:00:00 2001 From: "qingyi.liu" Date: Thu, 20 May 2021 15:22:05 +0800 Subject: [PATCH 10/47] =?UTF-8?q?update=20209.=E9=95=BF=E5=BA=A6=E6=9C=80?= =?UTF-8?q?=E5=B0=8F=E7=9A=84=E5=AD=90=E6=95=B0=E7=BB=84=20javascript?= =?UTF-8?q?=E7=89=88=E6=9C=AC?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- problems/0209.长度最小的子数组.md | 29 +++++++++++++---------- 1 file changed, 17 insertions(+), 12 deletions(-) diff --git a/problems/0209.长度最小的子数组.md b/problems/0209.长度最小的子数组.md index 0aaa466e..d5ad368d 100644 --- a/problems/0209.长度最小的子数组.md +++ b/problems/0209.长度最小的子数组.md @@ -175,19 +175,24 @@ Go： 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; }; ``` From e67b7acaecb03440cf644930a69f9f45bff04743 Mon Sep 17 00:00:00 2001 From: reoaah Date: Thu, 20 May 2021 15:25:52 +0800 Subject: [PATCH 11/47] =?UTF-8?q?=E6=B7=BB=E5=8A=A00746.=E4=BD=BF=E7=94=A8?= =?UTF-8?q?=E6=9C=80=E5=B0=8F=E8=8A=B1=E8=B4=B9=E7=88=AC=E6=A5=BC=E6=A2=AF?= =?UTF-8?q?.md=20Go=E7=89=88=E6=9C=AC?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- problems/0746.使用最小花费爬楼梯.md | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) diff --git a/problems/0746.使用最小花费爬楼梯.md b/problems/0746.使用最小花费爬楼梯.md index b8158205..aff56208 100644 --- a/problems/0746.使用最小花费爬楼梯.md +++ b/problems/0746.使用最小花费爬楼梯.md @@ -228,7 +228,23 @@ Python： Go： +```Go +func minCostClimbingStairs(cost []int) int { + dp := make([]int, len(cost)) + dp[0], dp[1] = cost[0], cost[1] + for i := 2; i < len(cost); i++ { + dp[i] = min(dp[i-1], dp[i-2]) + cost[i] + } + return min(dp[len(cost)-1], dp[len(cost)-2]) +} +func min(a, b int) int { + if a < b { + return a + } + return b +} +``` From 10a3433ba0b6b2a04c1a817c6dae0d2656a1a8b2 Mon Sep 17 00:00:00 2001 From: "qingyi.liu" Date: Thu, 20 May 2021 16:12:00 +0800 Subject: [PATCH 12/47] =?UTF-8?q?=E6=B7=BB=E5=8A=A059.=E8=9E=BA=E6=97=8B?= =?UTF-8?q?=E7=9F=A9=E9=98=B5IIjavaScript=E7=89=88=E6=9C=AC?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- problems/0059.螺旋矩阵II.md | 43 +++++++++++++++++++++++++++++++++ 1 file changed, 43 insertions(+) diff --git a/problems/0059.螺旋矩阵II.md b/problems/0059.螺旋矩阵II.md index 5e2d48d8..39cd2ffa 100644 --- a/problems/0059.螺旋矩阵II.md +++ b/problems/0059.螺旋矩阵II.md @@ -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; +}; +``` + ----------------------- From e4fddadb78b17a27395b9341fec749782b80b274 Mon Sep 17 00:00:00 2001 From: jojoo15 <75017412+jojoo15@users.noreply.github.com> Date: Thu, 20 May 2021 11:18:33 +0200 Subject: [PATCH 13/47] =?UTF-8?q?=E6=B7=BB=E5=8A=A0=200235.=E4=BA=8C?= =?UTF-8?q?=E5=8F=89=E6=A0=91=E7=9A=84=E6=9C=80=E8=BF=91=E5=85=AC=E5=85=B1?= =?UTF-8?q?=E7=A5=96=E5=85=88=20python=E7=89=88=E6=9C=AC?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 添加 0235.二叉树的最近公共祖先 python版本 --- ...35.二叉搜索树的最近公共祖先.md | 19 +++++++++++++++++-- 1 file changed, 17 insertions(+), 2 deletions(-) diff --git a/problems/0235.二叉搜索树的最近公共祖先.md b/problems/0235.二叉搜索树的最近公共祖先.md index 93642de5..64e9de3f 100644 --- a/problems/0235.二叉搜索树的最近公共祖先.md +++ b/problems/0235.二叉搜索树的最近公共祖先.md @@ -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) -
\ No newline at end of file +
From 398e2b754e4da7ec4291448f7922fdb258a7d5b1 Mon Sep 17 00:00:00 2001 From: weijiew <49638002+weijiew@users.noreply.github.com> Date: Thu, 20 May 2021 19:55:25 +0800 Subject: [PATCH 14/47] =?UTF-8?q?Update=200494.=E7=9B=AE=E6=A0=87=E5=92=8C?= =?UTF-8?q?.md?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- problems/0494.目标和.md | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/problems/0494.目标和.md b/problems/0494.目标和.md index 1782c88c..65d9b4e2 100644 --- a/problems/0494.目标和.md +++ b/problems/0494.目标和.md @@ -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) -
\ No newline at end of file +
From df2e37ba90bee63ef90fc2b73f4f1ddd80f45828 Mon Sep 17 00:00:00 2001 From: jojoo15 <75017412+jojoo15@users.noreply.github.com> Date: Thu, 20 May 2021 15:19:31 +0200 Subject: [PATCH 15/47] =?UTF-8?q?=E6=B7=BB=E5=8A=A0=200450.=E5=88=A0?= =?UTF-8?q?=E9=99=A4=E4=BA=8C=E5=8F=89=E6=90=9C=E7=B4=A2=E6=A0=91=E7=A7=8D?= =?UTF-8?q?=E7=9A=84=E8=8A=82=E7=82=B9=20python=E7=89=88=E6=9C=AC?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 添加 0450.删除二叉搜索树种的节点 python版本 --- .../0450.删除二叉搜索树中的节点.md | 40 ++++++++++++++++++- 1 file changed, 38 insertions(+), 2 deletions(-) diff --git a/problems/0450.删除二叉搜索树中的节点.md b/problems/0450.删除二叉搜索树中的节点.md index 604fb376..2cac8f87 100644 --- a/problems/0450.删除二叉搜索树中的节点.md +++ b/problems/0450.删除二叉搜索树中的节点.md @@ -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) -
\ No newline at end of file +
From 5e23ecc64e4e7251225de68d05a372f8bfbcb47a Mon Sep 17 00:00:00 2001 From: LiangDazhu <42199191+LiangDazhu@users.noreply.github.com> Date: Thu, 20 May 2021 23:07:09 +0800 Subject: [PATCH 16/47] =?UTF-8?q?Update=200763.=E5=88=92=E5=88=86=E5=AD=97?= =?UTF-8?q?=E6=AF=8D=E5=8C=BA=E9=97=B4.md?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Added python version code --- problems/0763.划分字母区间.md | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) diff --git a/problems/0763.划分字母区间.md b/problems/0763.划分字母区间.md index c1474280..a6ca0ea0 100644 --- a/problems/0763.划分字母区间.md +++ b/problems/0763.划分字母区间.md @@ -108,7 +108,23 @@ class Solution { ``` Python： +```python +class Solution: + def partitionLabels(self, s: str) -> List[int]: + hash = [0] * 26 + for i in range(len(s)): + hash[ord(s[i]) - ord('a')] = i + result = [] + left = 0 + right = 0 + for i in range(len(s)): + right = max(right, hash[ord(s[i]) - ord('a')]) + if i == right: + result.append(right - left + 1) + left = i + 1 + return result +``` Go： From 546b56f2d38ddb2d1d3b82a9e353051917030f87 Mon Sep 17 00:00:00 2001 From: LiangDazhu <42199191+LiangDazhu@users.noreply.github.com> Date: Thu, 20 May 2021 23:36:32 +0800 Subject: [PATCH 17/47] =?UTF-8?q?Update=200056.=E5=90=88=E5=B9=B6=E5=8C=BA?= =?UTF-8?q?=E9=97=B4.md?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Added python version code --- problems/0056.合并区间.md | 18 ++++++++++++++++-- 1 file changed, 16 insertions(+), 2 deletions(-) diff --git a/problems/0056.合并区间.md b/problems/0056.合并区间.md index e84a1634..69bccec5 100644 --- a/problems/0056.合并区间.md +++ b/problems/0056.合并区间.md @@ -168,7 +168,21 @@ 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： @@ -179,4 +193,4 @@ 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) -
\ No newline at end of file +
From 7133bbe6d1bfe16e04821a2fcce795bb7677ad43 Mon Sep 17 00:00:00 2001 From: X-shuffle <53906918+X-shuffle@users.noreply.github.com> Date: Thu, 20 May 2021 23:44:20 +0800 Subject: [PATCH 18/47] =?UTF-8?q?=E6=B7=BB=E5=8A=A0=20=E4=BA=8C=E5=8F=89?= =?UTF-8?q?=E6=A0=91=E7=9A=84=E7=BB=9F=E4=B8=80=E8=BF=AD=E4=BB=A3=E6=B3=95?= =?UTF-8?q?=20GO=E7=89=88=E6=9C=AC?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 添加 二叉树的统一迭代法 GO版本 --- problems/二叉树的统一迭代法.md | 130 ++++++++++++++++++++++++ 1 file changed, 130 insertions(+) diff --git a/problems/二叉树的统一迭代法.md b/problems/二叉树的统一迭代法.md index bc91eca0..bf3e83f4 100644 --- a/problems/二叉树的统一迭代法.md +++ b/problems/二叉树的统一迭代法.md @@ -242,7 +242,137 @@ Python： Go： +> 前序遍历统一迭代法 +```GO + /** + type Element struct { + // 元素保管的值 + Value interface{} + // 内含隐藏或非导出字段 +} + +func (l *List) Back() *Element +前序遍历：中左右 +压栈顺序：右左中 + **/ +func preorderTraversal(root *TreeNode) []int { + if root == nil { + return nil + } + var stack = list.New()//栈 + res:=[]int{}//结果集 + stack.PushBack(root) + var node *TreeNode + for stack.Len()>0{ + e := stack.Back() + stack.Remove(e)//弹出元素 + if e.Value==nil{// 如果为空，则表明是需要处理中间节点 + e=stack.Back()//弹出元素（即中间节点） + stack.Remove(e)//删除中间节点 + node=e.Value.(*TreeNode) + res=append(res,node.Val)//将中间节点加入到结果集中 + continue//继续弹出栈中下一个节点 + } + node = e.Value.(*TreeNode) + //压栈顺序：右左中 + if node.Right!=nil{ + stack.PushBack(node.Right) + } + if node.Left!=nil{ + stack.PushBack(node.Left) + } + stack.PushBack(node)//中间节点压栈后再压入nil作为中间节点的标志符 + stack.PushBack(nil) + } + return res + +} +``` + +> 中序遍历统一迭代法 + +```go +/** + * Definition for a binary tree node. + * type TreeNode struct { + * Val int + * Left *TreeNode + * Right *TreeNode + * } + */ + //中序遍历：左中右 + //压栈顺序：右中左 +func inorderTraversal(root *TreeNode) []int { + if root==nil{ + return nil + } + stack:=list.New()//栈 + res:=[]int{}//结果集 + stack.PushBack(root) + var node *TreeNode + for stack.Len()>0{ + e := stack.Back() + stack.Remove(e) + if e.Value==nil{// 如果为空，则表明是需要处理中间节点 + e=stack.Back()//弹出元素（即中间节点） + stack.Remove(e)//删除中间节点 + node=e.Value.(*TreeNode) + res=append(res,node.Val)//将中间节点加入到结果集中 + continue//继续弹出栈中下一个节点 + } + node = e.Value.(*TreeNode) + //压栈顺序：右中左 + if node.Right!=nil{ + stack.PushBack(node.Right) + } + stack.PushBack(node)//中间节点压栈后再压入nil作为中间节点的标志符 + stack.PushBack(nil) + if node.Left!=nil{ + stack.PushBack(node.Left) + } + } + return res +} +``` + +> 后序遍历统一迭代法 + +```go +//后续遍历：左右中 +//压栈顺序：中右左 +func postorderTraversal(root *TreeNode) []int { + if root == nil { + return nil + } + var stack = list.New()//栈 + res:=[]int{}//结果集 + stack.PushBack(root) + var node *TreeNode + for stack.Len()>0{ + e := stack.Back() + stack.Remove(e) + if e.Value==nil{// 如果为空，则表明是需要处理中间节点 + e=stack.Back()//弹出元素（即中间节点） + stack.Remove(e)//删除中间节点 + node=e.Value.(*TreeNode) + res=append(res,node.Val)//将中间节点加入到结果集中 + continue//继续弹出栈中下一个节点 + } + node = e.Value.(*TreeNode) + //压栈顺序：中右左 + stack.PushBack(node)//中间节点压栈后再压入nil作为中间节点的标志符 + stack.PushBack(nil) + if node.Right!=nil{ + stack.PushBack(node.Right) + } + if node.Left!=nil{ + stack.PushBack(node.Left) + } + } + return res +} +``` From 467461c24e569aab83bc954c3ba8a1e7fb4b7854 Mon Sep 17 00:00:00 2001 From: NevS <1173325467@qq.com> Date: Thu, 20 May 2021 23:51:45 +0800 Subject: [PATCH 19/47] =?UTF-8?q?=E6=B7=BB=E5=8A=A0=200209.=E9=95=BF?= =?UTF-8?q?=E5=BA=A6=E6=9C=80=E5=B0=8F=E7=9A=84=E5=AD=90=E6=95=B0=E7=BB=84?= =?UTF-8?q?=20go=20=E7=89=88=E6=9C=AC?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- problems/0209.长度最小的子数组.md | 26 ++++++++++++++++++++++- 1 file changed, 25 insertions(+), 1 deletion(-) diff --git a/problems/0209.长度最小的子数组.md b/problems/0209.长度最小的子数组.md index 0aaa466e..29f15581 100644 --- a/problems/0209.长度最小的子数组.md +++ b/problems/0209.长度最小的子数组.md @@ -172,6 +172,30 @@ 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: @@ -195,4 +219,4 @@ 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) -
\ No newline at end of file +
From 767c7fdccac05d404e7c1b1463e2b5a7d41c8aee Mon Sep 17 00:00:00 2001 From: tw2665 <55668073+tw2665@users.noreply.github.com> Date: Thu, 20 May 2021 16:26:12 -0400 Subject: [PATCH 20/47] add python solution to 0018.4sum --- problems/0018.四数之和.md | 32 ++++++++++++++++++++++++++++++++ 1 file changed, 32 insertions(+) diff --git a/problems/0018.四数之和.md b/problems/0018.四数之和.md index ff441bf7..5012c35e 100644 --- a/problems/0018.四数之和.md +++ b/problems/0018.四数之和.md @@ -165,7 +165,39 @@ class Solution { ``` Python： +```python3 +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： From 857ce0f8f5f5d5201c7ec16d74d6f4fa806f30c0 Mon Sep 17 00:00:00 2001 From: tw2665 <55668073+tw2665@users.noreply.github.com> Date: Thu, 20 May 2021 16:52:58 -0400 Subject: [PATCH 21/47] add python solution to 0541.reverseStrII --- problems/0541.反转字符串II.md | 30 ++++++++++++++++++++++++++++++ 1 file changed, 30 insertions(+) diff --git a/problems/0541.反转字符串II.md b/problems/0541.反转字符串II.md index 0a92ac8b..75ac39b0 100644 --- a/problems/0541.反转字符串II.md +++ b/problems/0541.反转字符串II.md @@ -134,6 +134,36 @@ class Solution { ``` Python： +```python3 + +class Solution(object): + def reverseStr(self, s, k): + """ + :type s: str + :type k: int + :rtype: str + """ + from functools import reduce + # turn s into a list + s = list(s) + + # another way to simply use a[::-1], but i feel this is easier to understand + def reverse(s): + left, right = 0, len(s) - 1 + while left < right: + s[left], s[right] = s[right], s[left] + left += 1 + right -= 1 + return s + + # make sure we reverse each 2k elements + for i in range(0, len(s), 2*k): + s[i:(i+k)] = reverse(s[i:(i+k)]) + + # combine list into str. + return reduce(lambda a, b: a+b, s) + +``` Go： From d232e0f20eba5435417159e6c4bde0c91d93c052 Mon Sep 17 00:00:00 2001 From: xll <18574553598@163.com> Date: Fri, 21 May 2021 09:50:39 +0800 Subject: [PATCH 22/47] =?UTF-8?q?0102=E4=BA=8C=E5=8F=89=E6=A0=91=E7=9A=84?= =?UTF-8?q?=E5=B1=82=E5=BA=8F=E9=81=8D=E5=8E=86javascript=E7=89=88?= =?UTF-8?q?=E6=9C=AC?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- problems/0102.二叉树的层序遍历.md | 29 +++++++++++++++++++++++ 1 file changed, 29 insertions(+) diff --git a/problems/0102.二叉树的层序遍历.md b/problems/0102.二叉树的层序遍历.md index 1cb4164f..22d4e5e5 100644 --- a/problems/0102.二叉树的层序遍历.md +++ b/problems/0102.二叉树的层序遍历.md @@ -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 Date: Fri, 21 May 2021 11:16:42 +0800 Subject: [PATCH 23/47] =?UTF-8?q?=E4=BA=8C=E5=8F=89=E6=A0=91=E7=9A=84?= =?UTF-8?q?=E5=B1=82=E5=BA=8F=E9=81=8D=E5=8E=86javascript=E7=89=88?= =?UTF-8?q?=E6=9C=AC?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- problems/0102.二叉树的层序遍历.md | 149 ++++++++++++++++++++++ 1 file changed, 149 insertions(+) diff --git a/problems/0102.二叉树的层序遍历.md b/problems/0102.二叉树的层序遍历.md index 1cb4164f..c40f4e2a 100644 --- a/problems/0102.二叉树的层序遍历.md +++ b/problems/0102.二叉树的层序遍历.md @@ -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;inode.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 From cdb78d1667230af61ab09d943d411fdaf2370a35 Mon Sep 17 00:00:00 2001 From: "qingyi.liu" Date: Fri, 21 May 2021 13:25:25 +0800 Subject: [PATCH 24/47] =?UTF-8?q?=E6=B7=BB=E5=8A=A0707.=E8=AE=BE=E8=AE=A1?= =?UTF-8?q?=E9=93=BE=E8=A1=A8JavaScript=E7=89=88=E6=9C=AC?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- problems/0707.设计链表.md | 136 ++++++++++++++++++++++++++++++++++ 1 file changed, 136 insertions(+) diff --git a/problems/0707.设计链表.md b/problems/0707.设计链表.md index 86cf623b..a4f4d8d3 100644 --- a/problems/0707.设计链表.md +++ b/problems/0707.设计链表.md @@ -393,6 +393,142 @@ class MyLinkedList: Go： +javaScript: + +```js + +class LinkNode { + constructor(val, next) { + this.val = val; + this.next = next; + } +} + +/** + * Initialize your data structure here. + * 单链表 储存头尾节点 和 节点数量 + */ +var MyLinkedList = function() { + this._size = 0; + this._tail = null; + this._head = null; +}; + +/** + * Get the value of the index-th node in the linked list. If the index is invalid, return -1. + * @param {number} index + * @return {number} + */ +MyLinkedList.prototype.getNode = function(index) { + if(index < 0 || index >= this._size) return null; + // 创建虚拟头节点 + let cur = new LinkNode(0, this._head); + // 0 -> head + while(index-- >= 0) { + cur = cur.next; + } + return cur; +}; +MyLinkedList.prototype.get = function(index) { + if(index < 0 || index >= this._size) return -1; + // 获取当前节点 + return this.getNode(index).val; +}; + +/** + * Add a node of value val before the first element of the linked list. After the insertion, the new node will be the first node of the linked list. + * @param {number} val + * @return {void} + */ +MyLinkedList.prototype.addAtHead = function(val) { + const node = new LinkNode(val, this._head); + this._head = node; + this._size++; + if(!this._tail) { + this._tail = node; + } +}; + +/** + * Append a node of value val to the last element of the linked list. + * @param {number} val + * @return {void} + */ +MyLinkedList.prototype.addAtTail = function(val) { + const node = new LinkNode(val, null); + this._size++; + if(this._tail) { + this._tail.next = node; + this._tail = node; + return; + } + this._tail = node; + this._head = node; +}; + +/** + * Add a node of value val before the index-th node in the linked list. If index equals to the length of linked list, the node will be appended to the end of linked list. If index is greater than the length, the node will not be inserted. + * @param {number} index + * @param {number} val + * @return {void} + */ +MyLinkedList.prototype.addAtIndex = function(index, val) { + if(index > this._size) return; + if(index <= 0) { + this.addAtHead(val); + return; + } + if(index === this._size) { + this.addAtTail(val); + return; + } + // 获取目标节点的上一个的节点 + const node = this.getNode(index - 1); + node.next = new LinkNode(val, node.next); + this._size++; +}; + +/** + * Delete the index-th node in the linked list, if the index is valid. + * @param {number} index + * @return {void} + */ +MyLinkedList.prototype.deleteAtIndex = function(index) { + if(index < 0 || index >= this._size) return; + if(index === 0) { + this._head = this._head.next; + this._size--; + return; + } + // 获取目标节点的上一个的节点 + const node = this.getNode(index - 1); + node.next = node.next.next; + // 处理尾节点 + if(index === this._size - 1) { + this._tail = node; + } + this._size--; +}; + +// MyLinkedList.prototype.out = function() { +// let cur = this._head; +// const res = []; +// while(cur) { +// res.push(cur.val); +// cur = cur.next; +// } +// }; +/** + * Your MyLinkedList object will be instantiated and called as such: + * var obj = new MyLinkedList() + * var param_1 = obj.get(index) + * obj.addAtHead(val) + * obj.addAtTail(val) + * obj.addAtIndex(index,val) + * obj.deleteAtIndex(index) + */ +``` + From 05bd25d17cea6219420a26f3f78715ee0ee9bb3a Mon Sep 17 00:00:00 2001 From: "qingyi.liu" Date: Fri, 21 May 2021 13:26:53 +0800 Subject: [PATCH 25/47] =?UTF-8?q?=E6=B7=BB=E5=8A=A0203.=E7=A7=BB=E9=99=A4?= =?UTF-8?q?=E9=93=BE=E8=A1=A8=E5=85=83=E7=B4=A0JavaScript=E7=89=88?= =?UTF-8?q?=E6=9C=AC?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- problems/0203.移除链表元素.md | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+) diff --git a/problems/0203.移除链表元素.md b/problems/0203.移除链表元素.md index 9fca1ee0..e268c9ac 100644 --- a/problems/0203.移除链表元素.md +++ b/problems/0203.移除链表元素.md @@ -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; +}; +``` + From 202e201919a1cf3d57821a0dce7d471152888fb0 Mon Sep 17 00:00:00 2001 From: "qingyi.liu" Date: Fri, 21 May 2021 14:05:46 +0800 Subject: [PATCH 26/47] =?UTF-8?q?=E6=B7=BB=E5=8A=A0206.=E5=8F=8D=E8=BD=AC?= =?UTF-8?q?=E9=93=BE=E8=A1=A8javaScript=E7=89=88=E6=9C=AC?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- problems/0206.翻转链表.md | 55 +++++++++++++++++++++++++++++++++++ 1 file changed, 55 insertions(+) diff --git a/problems/0206.翻转链表.md b/problems/0206.翻转链表.md index 886bbfcd..a6b3ca56 100644 --- a/problems/0206.翻转链表.md +++ b/problems/0206.翻转链表.md @@ -147,6 +147,61 @@ Python： Go： +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; +}; +``` + From 2aed976e4653c5ba42bdedf420fc57cb6a0a5c1f Mon Sep 17 00:00:00 2001 From: "qingyi.liu" Date: Fri, 21 May 2021 14:25:55 +0800 Subject: [PATCH 27/47] =?UTF-8?q?=E6=B7=BB=E5=8A=A0=E9=9D=A2=E8=AF=95?= =?UTF-8?q?=E9=A2=98=2002.07.=20=E9=93=BE=E8=A1=A8=E7=9B=B8=E4=BA=A4=20jav?= =?UTF-8?q?aScript=E7=89=88=E6=9C=AC?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- problems/面试题02.07.链表相交.md | 36 +++++++++++++++++++++++++ 1 file changed, 36 insertions(+) diff --git a/problems/面试题02.07.链表相交.md b/problems/面试题02.07.链表相交.md index 493438d7..6bc331b5 100644 --- a/problems/面试题02.07.链表相交.md +++ b/problems/面试题02.07.链表相交.md @@ -155,6 +155,42 @@ Python： Go： +javaScript: + +```js +/** + * @param {ListNode} headA + * @param {ListNode} headB + * @return {ListNode} + */ +var getListLen = function(head) { + let len = 0, cur = head; + while(cur) { + len++; + cur = cur.next; + } + return len; +} +var getIntersectionNode = function(headA, headB) { + let curA = headA,curB = headB, + lenA = getListLen(headA), + lenB = getListLen(headB); + if(lenA < lenB) { + [curA, curB] = [curB, curA]; + [lenA, lenB] = [lenB, lenA]; + } + let i = lenA - lenB; + while(i-- > 0) { + curA = curA.next + } + while(curA && curA !== curB) { + curA = curA.next; + curB = curB.next; + } + return curA; +}; +``` + From ada4d845425d6532b8507ef0b37605c91489e869 Mon Sep 17 00:00:00 2001 From: reoaah Date: Fri, 21 May 2021 15:30:55 +0800 Subject: [PATCH 28/47] =?UTF-8?q?=E6=B7=BB=E5=8A=A00062.=E4=B8=8D=E5=90=8C?= =?UTF-8?q?=E8=B7=AF=E5=BE=84.md=20Go=E7=89=88=E6=9C=AC?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- problems/0062.不同路径.md | 19 ++++++++++++++++++- 1 file changed, 18 insertions(+), 1 deletion(-) diff --git a/problems/0062.不同路径.md b/problems/0062.不同路径.md index e3a6da8c..680bba83 100644 --- a/problems/0062.不同路径.md +++ b/problems/0062.不同路径.md @@ -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] +} +``` From 20aa3a2454e955e17f37ecd2e22a56451e44fab4 Mon Sep 17 00:00:00 2001 From: gpfpter <67033145+gpfpter@users.noreply.github.com> Date: Fri, 21 May 2021 16:27:55 +0800 Subject: [PATCH 29/47] =?UTF-8?q?=E5=89=91=E6=8C=87=20Offer=2058=20-=20II.?= =?UTF-8?q?=20=E5=B7=A6=E6=97=8B=E8=BD=AC=E5=AD=97=E7=AC=A6=E4=B8=B2=20Jav?= =?UTF-8?q?a=E4=BB=A3=E7=A0=81=E6=8F=90=E4=BA=A4?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 剑指 Offer 58 - II. 左旋转字符串 Java代码提交，与作者思路相同的三次反转。 --- .../剑指Offer58-II.左旋转字符串.md | 23 ++++++++++++++++--- 1 file changed, 20 insertions(+), 3 deletions(-) diff --git a/problems/剑指Offer58-II.左旋转字符串.md b/problems/剑指Offer58-II.左旋转字符串.md index 3e9ab11f..9bd639aa 100644 --- a/problems/剑指Offer58-II.左旋转字符串.md +++ b/problems/剑指Offer58-II.左旋转字符串.md @@ -96,10 +96,27 @@ public: ## 其他语言版本 - Java： - - +```java +class Solution { + public String reverseLeftWords(String s, int n) { + int len=s.length(); + StringBuilder sb=new StringBuilder(s); + reverseString(sb,0,n-1); + reverseString(sb,n,len-1); + return sb.reverse().toString(); + } + public void reverseString(StringBuilder sb, int start, int end) { + while (start < end) { + char temp = sb.charAt(start); + sb.setCharAt(start, sb.charAt(end)); + sb.setCharAt(end, temp); + start++; + end--; + } + } +} +``` Python： From 472b57a40e611b2c7f76d82352c9f8657a580b2e Mon Sep 17 00:00:00 2001 From: Chen-Wang-JY <75002576+Chen-Wang-JY@users.noreply.github.com> Date: Fri, 21 May 2021 17:10:59 +0800 Subject: [PATCH 30/47] =?UTF-8?q?Update=200015.=E4=B8=89=E6=95=B0=E4=B9=8B?= =?UTF-8?q?=E5=92=8C.md?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 增加了Python3的双指针法 --- problems/0015.三数之和.md | 28 ++++++++++++++++++++++++++-- 1 file changed, 26 insertions(+), 2 deletions(-) diff --git a/problems/0015.三数之和.md b/problems/0015.三数之和.md index 96dc1ac3..9875f037 100644 --- a/problems/0015.三数之和.md +++ b/problems/0015.三数之和.md @@ -218,8 +218,32 @@ class Solution { ``` 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{ From 083918db7a4dc9f599dbbd84e29b63349f54a4a2 Mon Sep 17 00:00:00 2001 From: Chen-Wang-JY <75002576+Chen-Wang-JY@users.noreply.github.com> Date: Fri, 21 May 2021 17:14:12 +0800 Subject: [PATCH 31/47] =?UTF-8?q?Update=200015.=E4=B8=89=E6=95=B0=E4=B9=8B?= =?UTF-8?q?=E5=92=8C.md?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 添加了Python的双指针法 --- problems/0015.三数之和.md | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/problems/0015.三数之和.md b/problems/0015.三数之和.md index 9875f037..390ce864 100644 --- a/problems/0015.三数之和.md +++ b/problems/0015.三数之和.md @@ -218,7 +218,8 @@ class Solution { ``` Python： -```class Solution: +```Python +class Solution: def threeSum(self, nums): ans = [] n = len(nums) From db29574063ffa7d6613a3e60ec0eab448019be61 Mon Sep 17 00:00:00 2001 From: jojoo15 <75017412+jojoo15@users.noreply.github.com> Date: Fri, 21 May 2021 11:29:06 +0200 Subject: [PATCH 32/47] =?UTF-8?q?=E6=B7=BB=E5=8A=A0=200669.=E4=BF=AE?= =?UTF-8?q?=E5=89=AA=E4=BA=8C=E5=8F=89=E6=90=9C=E7=B4=A2=E6=A0=91=20python?= =?UTF-8?q?3=E7=89=88=E6=9C=AC?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 添加 0669.修剪二叉搜索树 python3版本 --- problems/0669.修剪二叉搜索树.md | 22 +++++++++++++++++++--- 1 file changed, 19 insertions(+), 3 deletions(-) diff --git a/problems/0669.修剪二叉搜索树.md b/problems/0669.修剪二叉搜索树.md index 8b9e1f6d..5c839b6c 100644 --- a/problems/0669.修剪二叉搜索树.md +++ b/problems/0669.修剪二叉搜索树.md @@ -265,8 +265,24 @@ 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 +class Solution: + def trimBST(self, root: TreeNode, low: int, high: int) -> TreeNode: + if not root: return root + if root.val < low: + return self.trimBST(root.right,low,high) // 寻找符合区间[low, high]的节点 + if root.val > high: + return self.trimBST(root.left,low,high) // 寻找符合区间[low, high]的节点 + root.left = self.trimBST(root.left,low,high) // root->left接入符合条件的左孩子 + root.right = self.trimBST(root.right,low,high) // root->right接入符合条件的右孩子 + return root +``` Go： @@ -276,4 +292,4 @@ 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) -
\ No newline at end of file +
From c6db1890eba10c69ebd0356161127f5a257e699e Mon Sep 17 00:00:00 2001 From: jojoo15 <75017412+jojoo15@users.noreply.github.com> Date: Fri, 21 May 2021 12:33:27 +0200 Subject: [PATCH 33/47] =?UTF-8?q?=E6=B7=BB=E5=8A=A0=200108.=E5=B0=86?= =?UTF-8?q?=E6=9C=89=E5=BA=8F=E6=95=B0=E7=BB=84=E8=BD=AC=E6=8D=A2=E4=B8=BA?= =?UTF-8?q?=E4=BA=8C=E5=8F=89=E6=90=9C=E7=B4=A2=E6=A0=91=20python3?= =?UTF-8?q?=E7=89=88=E6=9C=AC?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 添加 0108.将有序数组转换为二叉搜索树 python3版本 --- ...将有序数组转换为二叉搜索树.md | 24 +++++++++++++++++-- 1 file changed, 22 insertions(+), 2 deletions(-) diff --git a/problems/0108.将有序数组转换为二叉搜索树.md b/problems/0108.将有序数组转换为二叉搜索树.md index 93dc5fd6..139c3dae 100644 --- a/problems/0108.将有序数组转换为二叉搜索树.md +++ b/problems/0108.将有序数组转换为二叉搜索树.md @@ -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) -
\ No newline at end of file +
From f7828e65a3ef7518d23daca6741963e0288a9cc6 Mon Sep 17 00:00:00 2001 From: jojoo15 <75017412+jojoo15@users.noreply.github.com> Date: Fri, 21 May 2021 14:05:39 +0200 Subject: [PATCH 34/47] =?UTF-8?q?=E6=B7=BB=E5=8A=A0=200538.=E6=8A=8A?= =?UTF-8?q?=E4=BA=8C=E5=8F=89=E6=90=9C=E7=B4=A2=E6=A0=91=E8=BD=AC=E6=8D=A2?= =?UTF-8?q?=E4=B8=BA=E7=B4=AF=E5=8A=A0=E6=A0=91=20python3=E7=89=88?= =?UTF-8?q?=E6=9C=AC?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 添加 0538.把二叉搜索树转换为累加树 python3版本 --- ...38.把二叉搜索树转换为累加树.md | 24 ++++++++++++++++--- 1 file changed, 21 insertions(+), 3 deletions(-) diff --git a/problems/0538.把二叉搜索树转换为累加树.md b/problems/0538.把二叉搜索树转换为累加树.md index 209c989b..cc19bb30 100644 --- a/problems/0538.把二叉搜索树转换为累加树.md +++ b/problems/0538.把二叉搜索树转换为累加树.md @@ -196,8 +196,26 @@ 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 convertBST(self, root: TreeNode) -> TreeNode: + def buildalist(root): + if not root: return None + buildalist(root.right) #右中左遍历 + root.val += self.pre + self.pre = root.val + buildalist(root.left) + self.pre = 0 #记录前一个节点的数值 + buildalist(root) + return root +``` Go： @@ -207,4 +225,4 @@ 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) -
\ No newline at end of file +
From 5fe52a501996d9a11178647cb3748b6484fa21d6 Mon Sep 17 00:00:00 2001 From: tw2665 <55668073+tw2665@users.noreply.github.com> Date: Fri, 21 May 2021 09:31:00 -0400 Subject: [PATCH 35/47] add python solution for 0541.reverseStrII code block head change to python --- problems/0541.反转字符串II.md | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/problems/0541.反转字符串II.md b/problems/0541.反转字符串II.md index 75ac39b0..6171613f 100644 --- a/problems/0541.反转字符串II.md +++ b/problems/0541.反转字符串II.md @@ -134,7 +134,7 @@ class Solution { ``` Python： -```python3 +```python class Solution(object): def reverseStr(self, s, k): From 8b862a548cb2a546da65f586e21f79b21cd11967 Mon Sep 17 00:00:00 2001 From: tw2665 <55668073+tw2665@users.noreply.github.com> Date: Fri, 21 May 2021 09:34:54 -0400 Subject: [PATCH 36/47] add python solution fot 0018.4sum correct format. --- problems/0018.四数之和.md | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/problems/0018.四数之和.md b/problems/0018.四数之和.md index 5012c35e..c1f3cb7f 100644 --- a/problems/0018.四数之和.md +++ b/problems/0018.四数之和.md @@ -165,7 +165,7 @@ class Solution { ``` Python： -```python3 +```python class Solution(object): def fourSum(self, nums, target): From a7f3d2ddd615ea4e33cbe11138d6adf426722ec0 Mon Sep 17 00:00:00 2001 From: LiangDazhu <42199191+LiangDazhu@users.noreply.github.com> Date: Fri, 21 May 2021 23:51:55 +0800 Subject: [PATCH 37/47] =?UTF-8?q?Update=200738.=E5=8D=95=E8=B0=83=E9=80=92?= =?UTF-8?q?=E5=A2=9E=E7=9A=84=E6=95=B0=E5=AD=97.md?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Added python version code --- problems/0738.单调递增的数字.md | 19 ++++++++++++++++--- 1 file changed, 16 insertions(+), 3 deletions(-) diff --git a/problems/0738.单调递增的数字.md b/problems/0738.单调递增的数字.md index dc136028..4324a0bc 100644 --- a/problems/0738.单调递增的数字.md +++ b/problems/0738.单调递增的数字.md @@ -8,6 +8,7 @@ ## 738.单调递增的数字 +题目链接: https://leetcode-cn.com/problems/monotone-increasing-digits/ 给定一个非负整数 N，找出小于或等于 N 的最大的整数，同时这个整数需要满足其各个位数上的数字是单调递增。 @@ -30,7 +31,7 @@ ## 暴力解法 -题意很简单，那么首先想的就是暴力解法了，来我提大家暴力一波，结果自然是超时！ +题意很简单，那么首先想的就是暴力解法了，来我替大家暴力一波，结果自然是超时！ 代码如下： ```C++ @@ -146,7 +147,19 @@ class Solution { Python： - +```python +class Solution: + def monotoneIncreasingDigits(self, n: int) -> int: + strNum = list(str(n)) + flag = len(strNum) + for i in range(len(strNum) - 1, 0, -1): + if int(strNum[i]) < int(strNum[i - 1]): + strNum[i - 1] = str(int(strNum[i - 1]) - 1) + flag = i + for i in range(flag, len(strNum)): + strNum[i] = '9' + return int("".join(strNum)) +``` Go： @@ -157,4 +170,4 @@ 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) -
\ No newline at end of file +
From fc04e9ec1ee596adf438224e82633142871b676b Mon Sep 17 00:00:00 2001 From: "qingyi.liu" Date: Sat, 22 May 2021 10:16:13 +0800 Subject: [PATCH 38/47] =?UTF-8?q?=E6=B7=BB=E5=8A=A0242.=E6=9C=89=E6=95=88?= =?UTF-8?q?=E7=9A=84=E5=AD=97=E6=AF=8D=E5=BC=82=E4=BD=8D=E8=AF=8DJavaScrip?= =?UTF-8?q?t=E7=89=88=E6=9C=AC?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- problems/0242.有效的字母异位词.md | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) diff --git a/problems/0242.有效的字母异位词.md b/problems/0242.有效的字母异位词.md index 10939b0f..8aa0d171 100644 --- a/problems/0242.有效的字母异位词.md +++ b/problems/0242.有效的字母异位词.md @@ -140,6 +140,23 @@ func isAnagram(s string, t string) bool { } ``` +javaScript: + +```js +var isAnagram = function(s, t) { + const resSet = new Array(25).fill(0); + const base = "a".charCodeAt(); + for(const i of s) { + resSet[i.charCodeAt() - base]++; + } + for(const i of t) { + resSet[i.charCodeAt() - base]--; + // if(val < 0) return false; + } + return resSet.every(i => !i); +}; +``` + ## 相关题目 * 383.赎金信 From 139761a07729b450bad3ac9b4ee50ff1337c575e Mon Sep 17 00:00:00 2001 From: "qingyi.liu" Date: Sat, 22 May 2021 10:30:01 +0800 Subject: [PATCH 39/47] =?UTF-8?q?=E6=B7=BB=E5=8A=A0349.=20=E4=B8=A4?= =?UTF-8?q?=E4=B8=AA=E6=95=B0=E7=BB=84=E7=9A=84=E4=BA=A4=E9=9B=86JavaScrip?= =?UTF-8?q?t=E7=89=88=E6=9C=AC?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- problems/0349.两个数组的交集.md | 28 ++++++++++++++++++++++++++ 1 file changed, 28 insertions(+) diff --git a/problems/0349.两个数组的交集.md b/problems/0349.两个数组的交集.md index b5116ee1..93d2c2d4 100644 --- a/problems/0349.两个数组的交集.md +++ b/problems/0349.两个数组的交集.md @@ -113,6 +113,34 @@ 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); +}; +``` + From 0a2679ea0be39e55b1ef3c7569e7db1740d79df7 Mon Sep 17 00:00:00 2001 From: "qingyi.liu" Date: Sat, 22 May 2021 11:23:48 +0800 Subject: [PATCH 40/47] =?UTF-8?q?=E6=B7=BB=E5=8A=A0=E7=AC=AC454=E9=A2=98.?= =?UTF-8?q?=E5=9B=9B=E6=95=B0=E7=9B=B8=E5=8A=A0IIJavaScript=E7=89=88?= =?UTF-8?q?=E6=9C=AC?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- problems/0454.四数相加II.md | 32 ++++++++++++++++++++++++++++++++ 1 file changed, 32 insertions(+) diff --git a/problems/0454.四数相加II.md b/problems/0454.四数相加II.md index ad928a3f..28db6a50 100644 --- a/problems/0454.四数相加II.md +++ b/problems/0454.四数相加II.md @@ -155,6 +155,38 @@ class Solution(object): 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; +}; +``` + From 7699a818b42a4cf517553b0cd99b1a3a8ed07f0a Mon Sep 17 00:00:00 2001 From: "qingyi.liu" Date: Sat, 22 May 2021 11:33:52 +0800 Subject: [PATCH 41/47] =?UTF-8?q?=E6=B7=BB=E5=8A=A0383.=20=E8=B5=8E?= =?UTF-8?q?=E9=87=91=E4=BF=A1JavaScript=E7=89=88=E6=9C=AC?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- problems/0383.赎金信.md | 24 +++++++++++++++++++++++- 1 file changed, 23 insertions(+), 1 deletion(-) diff --git a/problems/0383.赎金信.md b/problems/0383.赎金信.md index 527945fa..7ff28601 100644 --- a/problems/0383.赎金信.md +++ b/problems/0383.赎金信.md @@ -136,7 +136,7 @@ class Solution { ``` Python： -``` +```py class Solution(object): def canConstruct(self, ransomNote, magazine): """ @@ -167,6 +167,28 @@ class Solution(object): Go： +javaScript: + +```js +/** + * @param {string} ransomNote + * @param {string} magazine + * @return {boolean} + */ +var canConstruct = function(ransomNote, magazine) { + const strArr = new Array(25).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; +}; +``` From 3be6a9dd2bb44a54721460f503a6606644902d98 Mon Sep 17 00:00:00 2001 From: "qingyi.liu" Date: Sat, 22 May 2021 13:38:18 +0800 Subject: [PATCH 42/47] =?UTF-8?q?=E6=B7=BB=E5=8A=A0=E7=AC=AC15=E9=A2=98.?= =?UTF-8?q?=20=E4=B8=89=E6=95=B0=E4=B9=8B=E5=92=8CJavaScript=E7=89=88?= =?UTF-8?q?=E6=9C=AC?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- problems/0015.三数之和.md | 53 +++++++++++++++++++++++++++++++++++ 1 file changed, 53 insertions(+) diff --git a/problems/0015.三数之和.md b/problems/0015.三数之和.md index 96dc1ac3..8ee1d07b 100644 --- a/problems/0015.三数之和.md +++ b/problems/0015.三数之和.md @@ -256,6 +256,59 @@ 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; +}; +``` From 72eadd2b28fcb58be0e9531b2c7b1afc56006ea9 Mon Sep 17 00:00:00 2001 From: QuinnDK <39618652+QuinnDK@users.noreply.github.com> Date: Sat, 22 May 2021 16:39:30 +0800 Subject: [PATCH 43/47] =?UTF-8?q?Update=200056.=E5=90=88=E5=B9=B6=E5=8C=BA?= =?UTF-8?q?=E9=97=B4.md?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- problems/0056.合并区间.md | 27 ++++++++++++++++++++++++++- 1 file changed, 26 insertions(+), 1 deletion(-) diff --git a/problems/0056.合并区间.md b/problems/0056.合并区间.md index e84a1634..85719a25 100644 --- a/problems/0056.合并区间.md +++ b/problems/0056.合并区间.md @@ -171,7 +171,32 @@ Python： Go： +```Go +func merge(intervals [][]int) [][]int { + sort.Slice(intervals, func(i, j int) bool { + return intervals[i][0] b { return a } + return b +} +``` @@ -179,4 +204,4 @@ 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) -
\ No newline at end of file +
From 2b6f7484de2b731e8b03580c45f1681f8fddff5e Mon Sep 17 00:00:00 2001 From: "qingyi.liu" Date: Sat, 22 May 2021 22:40:23 +0800 Subject: [PATCH 44/47] =?UTF-8?q?update242.=E6=9C=89=E6=95=88=E7=9A=84?= =?UTF-8?q?=E5=AD=97=E6=AF=8D=E5=BC=82=E4=BD=8D=E8=AF=8D?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- problems/0242.有效的字母异位词.md | 12 +++++++++--- problems/0383.赎金信.md | 2 +- 2 files changed, 10 insertions(+), 4 deletions(-) diff --git a/problems/0242.有效的字母异位词.md b/problems/0242.有效的字母异位词.md index 8aa0d171..0c75bbf9 100644 --- a/problems/0242.有效的字母异位词.md +++ b/problems/0242.有效的字母异位词.md @@ -143,17 +143,23 @@ func isAnagram(s string, t string) bool { javaScript: ```js +/** + * @param {string} s + * @param {string} t + * @return {boolean} + */ var isAnagram = function(s, t) { - const resSet = new Array(25).fill(0); + 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]--; - // if(val < 0) return false; } - return resSet.every(i => !i); + return true; }; ``` diff --git a/problems/0383.赎金信.md b/problems/0383.赎金信.md index 7ff28601..755910f9 100644 --- a/problems/0383.赎金信.md +++ b/problems/0383.赎金信.md @@ -176,7 +176,7 @@ javaScript: * @return {boolean} */ var canConstruct = function(ransomNote, magazine) { - const strArr = new Array(25).fill(0), + const strArr = new Array(26).fill(0), base = "a".charCodeAt(); for(const s of magazine) { strArr[s.charCodeAt() - base]++; From 29fdafecc4f649369f7ceb7f6a022c3f405499af Mon Sep 17 00:00:00 2001 From: LiangDazhu <42199191+LiangDazhu@users.noreply.github.com> Date: Sat, 22 May 2021 23:01:54 +0800 Subject: [PATCH 45/47] =?UTF-8?q?Update=200714.=E4=B9=B0=E5=8D=96=E8=82=A1?= =?UTF-8?q?=E7=A5=A8=E7=9A=84=E6=9C=80=E4=BD=B3=E6=97=B6=E6=9C=BA=E5=90=AB?= =?UTF-8?q?=E6=89=8B=E7=BB=AD=E8=B4=B9.md?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Added python version code --- ...14.买卖股票的最佳时机含手续费.md | 16 +++++++++++++++- 1 file changed, 15 insertions(+), 1 deletion(-) diff --git a/problems/0714.买卖股票的最佳时机含手续费.md b/problems/0714.买卖股票的最佳时机含手续费.md index 99f01197..f4295da2 100644 --- a/problems/0714.买卖股票的最佳时机含手续费.md +++ b/problems/0714.买卖股票的最佳时机含手续费.md @@ -199,7 +199,21 @@ class Solution { // 动态规划 Python： - +```python +class Solution: # 贪心思路 + def maxProfit(self, prices: List[int], fee: int) -> int: + result = 0 + minPrice = prices[0] + for i in range(1, len(prices)): + if prices[i] < minPrice: + minPrice = prices[i] + elif prices[i] >= minPrice and prices[i] <= minPrice + fee: + continue + else: + result += prices[i] - minPrice - fee + minPrice = prices[i] - fee + return result +``` Go： From 957a284c60ef4c34241982df5f76dacf61134d74 Mon Sep 17 00:00:00 2001 From: "qingyi.liu" Date: Sat, 22 May 2021 23:37:30 +0800 Subject: [PATCH 46/47] =?UTF-8?q?=E6=B7=BB=E5=8A=A0=E7=AC=AC18=E9=A2=98.?= =?UTF-8?q?=20=E5=9B=9B=E6=95=B0=E4=B9=8B=E5=92=8CjavaScript=E7=89=88?= =?UTF-8?q?=E6=9C=AC?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- problems/0018.四数之和.md | 32 ++++++++++++++++++++++++++++++++ 1 file changed, 32 insertions(+) diff --git a/problems/0018.四数之和.md b/problems/0018.四数之和.md index ff441bf7..067386bb 100644 --- a/problems/0018.四数之和.md +++ b/problems/0018.四数之和.md @@ -169,7 +169,39 @@ Python： 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; +}; +``` ----------------------- From d8603ed0325687b1c54928db3aec2e99672710ba Mon Sep 17 00:00:00 2001 From: xll <18574553598@163.com> Date: Sun, 23 May 2021 10:26:07 +0800 Subject: [PATCH 47/47] =?UTF-8?q?0226.=E7=BF=BB=E8=BD=AC=E4=BA=8C=E5=8F=89?= =?UTF-8?q?=E6=A0=91=E7=9A=84JavaScript=E7=89=88=E6=9C=AC?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- problems/0226.翻转二叉树.md | 92 +++++++++++++++++++++++++++++++- 1 file changed, 91 insertions(+), 1 deletion(-) diff --git a/problems/0226.翻转二叉树.md b/problems/0226.翻转二叉树.md index 3b96b4f6..968cfa4a 100644 --- a/problems/0226.翻转二叉树.md +++ b/problems/0226.翻转二叉树.md @@ -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) -
\ No newline at end of file +