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Merge branch 'youngyangyang04:master' into master

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JaneyLin
2022-06-21 16:27:54 -05:00
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85
problems/0042.接雨水.md
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@ -744,6 +744,91 @@ var trap = function(height) {
};
```
### TypeScript
双指针法：
```typescript
function trap(height: number[]): number {
const length: number = height.length;
let resVal: number = 0;
for (let i = 0; i < length; i++) {
let leftMaxHeight: number = height[i],
rightMaxHeight: number = height[i];
let leftIndex: number = i - 1,
rightIndex: number = i + 1;
while (leftIndex >= 0) {
if (height[leftIndex] > leftMaxHeight)
leftMaxHeight = height[leftIndex];
leftIndex--;
}
while (rightIndex < length) {
if (height[rightIndex] > rightMaxHeight)
rightMaxHeight = height[rightIndex];
rightIndex++;
}
resVal += Math.min(leftMaxHeight, rightMaxHeight) - height[i];
}
return resVal;
};
```
动态规划：
```typescript
function trap(height: number[]): number {
const length: number = height.length;
const leftMaxHeightDp: number[] = [],
rightMaxHeightDp: number[] = [];
leftMaxHeightDp[0] = height[0];
rightMaxHeightDp[length - 1] = height[length - 1];
for (let i = 1; i < length; i++) {
leftMaxHeightDp[i] = Math.max(height[i], leftMaxHeightDp[i - 1]);
}
for (let i = length - 2; i >= 0; i--) {
rightMaxHeightDp[i] = Math.max(height[i], rightMaxHeightDp[i + 1]);
}
let resVal: number = 0;
for (let i = 0; i < length; i++) {
resVal += Math.min(leftMaxHeightDp[i], rightMaxHeightDp[i]) - height[i];
}
return resVal;
};
```
单调栈：
```typescript
function trap(height: number[]): number {
const length: number = height.length;
const stack: number[] = [];
stack.push(0);
let resVal: number = 0;
for (let i = 1; i < length; i++) {
let top = stack[stack.length - 1];
if (height[top] > height[i]) {
stack.push(i);
} else if (height[top] === height[i]) {
stack.pop();
stack.push(i);
} else {
while (stack.length > 0 && height[top] < height[i]) {
let mid = stack.pop();
if (stack.length > 0) {
let left = stack[stack.length - 1];
let h = Math.min(height[left], height[i]) - height[mid];
let w = i - left - 1;
resVal += h * w;
top = stack[stack.length - 1];
}
}
stack.push(i);
}
}
return resVal;
};
```
### C:
一种更简便的双指针方法：

90
problems/0084.柱状图中最大的矩形.md
View File

@ -486,5 +486,95 @@ var largestRectangleArea = function(heights) {
return maxArea;
};
```
TypeScript：
> 双指针法（会超时）：
```typescript
function largestRectangleArea(heights: number[]): number {
let resMax: number = 0;
for (let i = 0, length = heights.length; i < length; i++) {
// 左开右开
let left: number = i - 1,
right: number = i + 1;
while (left >= 0 && heights[left] >= heights[i]) {
left--;
}
while (right < length && heights[right] >= heights[i]) {
right++;
}
resMax = Math.max(resMax, heights[i] * (right - left - 1));
}
return resMax;
};
```
> 动态规划预处理：
```typescript
function largestRectangleArea(heights: number[]): number {
const length: number = heights.length;
const leftHeightDp: number[] = [],
rightHeightDp: number[] = [];
leftHeightDp[0] = -1;
rightHeightDp[length - 1] = length;
for (let i = 1; i < length; i++) {
let j = i - 1;
while (j >= 0 && heights[i] <= heights[j]) {
j = leftHeightDp[j];
}
leftHeightDp[i] = j;
}
for (let i = length - 2; i >= 0; i--) {
let j = i + 1;
while (j < length && heights[i] <= heights[j]) {
j = rightHeightDp[j];
}
rightHeightDp[i] = j;
}
let resMax: number = 0;
for (let i = 0; i < length; i++) {
let area = heights[i] * (rightHeightDp[i] - leftHeightDp[i] - 1);
resMax = Math.max(resMax, area);
}
return resMax;
};
```
> 单调栈：
```typescript
function largestRectangleArea(heights: number[]): number {
heights.push(0);
const length: number = heights.length;
// 栈底->栈顶：严格单调递增
const stack: number[] = [];
stack.push(0);
let resMax: number = 0;
for (let i = 1; i < length; i++) {
let top = stack[stack.length - 1];
if (heights[top] < heights[i]) {
stack.push(i);
} else if (heights[top] === heights[i]) {
stack.pop();
stack.push(i);
} else {
while (stack.length > 0 && heights[top] > heights[i]) {
let mid = stack.pop();
let left = stack.length > 0 ? stack[stack.length - 1] : -1;
let w = i - left - 1;
let h = heights[mid];
resMax = Math.max(resMax, w * h);
top = stack[stack.length - 1];
}
stack.push(i);
}
}
return resMax;
};
```
-----------------------
<div align="center"><img src=https://code-thinking.cdn.bcebos.com/pics/01二维码一.jpg width=500> </img></div>

99
problems/0104.二叉树的最大深度.md
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@ -495,7 +495,7 @@ class solution:
## go
### 104.二叉树的最大深度
```go
/**
* definition for a binary tree node.
@ -548,6 +548,8 @@ func maxdepth(root *treenode) int {
## javascript
### 104.二叉树的最大深度
```javascript
var maxdepth = function(root) {
if (root === null) return 0;
@ -595,6 +597,8 @@ var maxDepth = function(root) {
};
```
### 559.n叉树的最大深度
N叉树的最大深度 递归写法
```js
var maxDepth = function(root) {
@ -627,9 +631,9 @@ var maxDepth = function(root) {
};
```
## TypeScript：
## TypeScript
> 二叉树的最大深度：
### 104.二叉树的最大深度
```typescript
// 后续遍历（自下而上）
@ -672,7 +676,7 @@ function maxDepth(root: TreeNode | null): number {
};
```
> N叉树的最大深度
### 559.n叉树的最大深度
```typescript
// 后续遍历（自下而上）
@ -702,6 +706,8 @@ function maxDepth(root: TreeNode | null): number {
## C
### 104.二叉树的最大深度
二叉树最大深度递归
```c
int maxDepth(struct TreeNode* root){
@ -758,7 +764,8 @@ int maxDepth(struct TreeNode* root){
## Swift
>二叉树最大深度
### 104.二叉树的最大深度
```swift
// 递归 - 后序
func maxDepth1(_ root: TreeNode?) -> Int {
@ -797,7 +804,8 @@ func maxDepth(_ root: TreeNode?) -> Int {
}
```
>N叉树最大深度
### 559.n叉树的最大深度
```swift
// 递归
func maxDepth(_ root: Node?) -> Int {
@ -833,5 +841,84 @@ func maxDepth1(_ root: Node?) -> Int {
}
```
## Scala
### 104.二叉树的最大深度
递归法:
```scala
object Solution {
def maxDepth(root: TreeNode): Int = {
def process(curNode: TreeNode): Int = {
if (curNode == null) return 0
// 递归左节点和右节点，返回最大的，最后+1
math.max(process(curNode.left), process(curNode.right)) + 1
}
// 调用递归方法，return关键字可以省略
process(root)
}
}
```
迭代法:
```scala
object Solution {
import scala.collection.mutable
def maxDepth(root: TreeNode): Int = {
var depth = 0
if (root == null) return depth
val queue = mutable.Queue[TreeNode]()
queue.enqueue(root)
while (!queue.isEmpty) {
val len = queue.size
for (i <- 0 until len) {
val curNode = queue.dequeue()
if (curNode.left != null) queue.enqueue(curNode.left)
if (curNode.right != null) queue.enqueue(curNode.right)
}
depth += 1 // 只要有层次就+=1
}
depth
}
}
```
### 559.n叉树的最大深度
递归法:
```scala
object Solution {
def maxDepth(root: Node): Int = {
if (root == null) return 0
var depth = 0
for (node <- root.children) {
depth = math.max(depth, maxDepth(node))
}
depth + 1
}
}
```
迭代法: (层序遍历)
```scala
object Solution {
import scala.collection.mutable
def maxDepth(root: Node): Int = {
if (root == null) return 0
var depth = 0
val queue = mutable.Queue[Node]()
queue.enqueue(root)
while (!queue.isEmpty) {
val len = queue.size
depth += 1
for (i <- 0 until len) {
val curNode = queue.dequeue()
for (node <- curNode.children) queue.enqueue(node)
}
}
depth
}
}
```
-----------------------
<div align="center"><img src=https://code-thinking.cdn.bcebos.com/pics/01二维码一.jpg width=500> </img></div>

41
problems/0111.二叉树的最小深度.md
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@ -488,6 +488,46 @@ func minDepth(_ root: TreeNode?) -> Int {
}
```
## Scala
递归法:
```scala
object Solution {
def minDepth(root: TreeNode): Int = {
if (root == null) return 0
if (root.left == null && root.right != null) return 1 + minDepth(root.right)
if (root.left != null && root.right == null) return 1 + minDepth(root.left)
// 如果两侧都不为空，则取最小值，return关键字可以省略
1 + math.min(minDepth(root.left), minDepth(root.right))
}
}
```
迭代法:
```scala
object Solution {
import scala.collection.mutable
def minDepth(root: TreeNode): Int = {
if (root == null) return 0
var depth = 0
val queue = mutable.Queue[TreeNode]()
queue.enqueue(root)
while (!queue.isEmpty) {
depth += 1
val len = queue.size
for (i <- 0 until len) {
val curNode = queue.dequeue()
if (curNode.left != null) queue.enqueue(curNode.left)
if (curNode.right != null) queue.enqueue(curNode.right)
if (curNode.left == null && curNode.right == null) return depth
}
}
depth
}
}
```
rust:
```rust
impl Solution {
@ -550,6 +590,7 @@ impl Solution {
}
min_depth
}
```
-----------------------

31
problems/0496.下一个更大元素I.md
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@ -332,5 +332,36 @@ var nextGreaterElement = function (nums1, nums2) {
};
```
TypeScript：
```typescript
function nextGreaterElement(nums1: number[], nums2: number[]): number[] {
const resArr: number[] = new Array(nums1.length).fill(-1);
const stack: number[] = [];
const helperMap: Map<number, number> = new Map();
nums1.forEach((num, index) => {
helperMap.set(num, index);
})
stack.push(0);
for (let i = 1, length = nums2.length; i < length; i++) {
let top = stack[stack.length - 1];
while (stack.length > 0 && nums2[top] < nums2[i]) {
let index = helperMap.get(nums2[top]);
if (index !== undefined) {
resArr[index] = nums2[i];
}
stack.pop();
top = stack[stack.length - 1];
}
if (helperMap.get(nums2[i]) !== undefined) {
stack.push(i);
}
}
return resArr;
};
```
-----------------------
<div align="center"><img src=https://code-thinking.cdn.bcebos.com/pics/01二维码一.jpg width=500> </img></div>

26
problems/0503.下一个更大元素II.md
View File

@ -182,5 +182,31 @@ var nextGreaterElements = function (nums) {
return res;
};
```
TypeScript：
```typescript
function nextGreaterElements(nums: number[]): number[] {
const length: number = nums.length;
const stack: number[] = [];
stack.push(0);
const resArr: number[] = new Array(length).fill(-1);
for (let i = 1; i < length * 2; i++) {
const index = i % length;
let top = stack[stack.length - 1];
while (stack.length > 0 && nums[top] < nums[index]) {
resArr[top] = nums[index];
stack.pop();
top = stack[stack.length - 1];
}
if (i < length) {
stack.push(i);
}
}
return resArr;
};
```
-----------------------
<div align="center"><img src=https://code-thinking.cdn.bcebos.com/pics/01二维码一.jpg width=500> </img></div>

29
problems/0516.最长回文子序列.md
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@ -235,6 +235,35 @@ const longestPalindromeSubseq = (s) => {
};
```
TypeScript：
```typescript
function longestPalindromeSubseq(s: string): number {
/**
dp[i][j]：[i,j]区间内，最长回文子序列的长度
*/
const length: number = s.length;
const dp: number[][] = new Array(length).fill(0)
.map(_ => new Array(length).fill(0));
for (let i = 0; i < length; i++) {
dp[i][i] = 1;
}
// 自下而上，自左往右遍历
for (let i = length - 1; i >= 0; i--) {
for (let j = i + 1; j < length; j++) {
if (s[i] === s[j]) {
dp[i][j] = dp[i + 1][j - 1] + 2;
} else {
dp[i][j] = Math.max(dp[i][j - 1], dp[i + 1][j]);
}
}
}
return dp[0][length - 1];
};
```
-----------------------
<div align="center"><img src=https://code-thinking.cdn.bcebos.com/pics/01二维码一.jpg width=500> </img></div>

26
problems/0739.每日温度.md
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@ -372,6 +372,32 @@ var dailyTemperatures = function(temperatures) {
};
```
TypeScript:
> 精简版：
```typescript
function dailyTemperatures(temperatures: number[]): number[] {
const length: number = temperatures.length;
const stack: number[] = [];
const resArr: number[] = new Array(length).fill(0);
stack.push(0);
for (let i = 1; i < length; i++) {
let top = stack[stack.length - 1];
while (
stack.length > 0 &&
temperatures[top] < temperatures[i]
) {
resArr[top] = i - top;
stack.pop();
top = stack[stack.length - 1];
}
stack.push(i);
}
return resArr;
};
```