diff --git a/problems/0042.接雨水.md b/problems/0042.接雨水.md index b232ce22..060c0b45 100644 --- a/problems/0042.接雨水.md +++ b/problems/0042.接雨水.md @@ -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: diff --git a/problems/0084.柱状图中最大的矩形.md b/problems/0084.柱状图中最大的矩形.md index 439a3bc5..8f10a582 100644 --- a/problems/0084.柱状图中最大的矩形.md +++ b/problems/0084.柱状图中最大的矩形.md @@ -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; +}; +``` + + + -----------------------
diff --git a/problems/0104.二叉树的最大深度.md b/problems/0104.二叉树的最大深度.md index 65a155fb..4714685b 100644 --- a/problems/0104.二叉树的最大深度.md +++ b/problems/0104.二叉树的最大深度.md @@ -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 + } +} +``` + -----------------------
diff --git a/problems/0111.二叉树的最小深度.md b/problems/0111.二叉树的最小深度.md index b1331659..da24480a 100644 --- a/problems/0111.二叉树的最小深度.md +++ b/problems/0111.二叉树的最小深度.md @@ -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 } + ``` ----------------------- diff --git a/problems/0496.下一个更大元素I.md b/problems/0496.下一个更大元素I.md index 02339677..274cc32b 100644 --- a/problems/0496.下一个更大元素I.md +++ b/problems/0496.下一个更大元素I.md @@ -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 = 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; +}; +``` + + + -----------------------
diff --git a/problems/0503.下一个更大元素II.md b/problems/0503.下一个更大元素II.md index ace4d40b..33807d26 100644 --- a/problems/0503.下一个更大元素II.md +++ b/problems/0503.下一个更大元素II.md @@ -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; +}; +``` + + + -----------------------
diff --git a/problems/0516.最长回文子序列.md b/problems/0516.最长回文子序列.md index 63120b14..33de8fd1 100644 --- a/problems/0516.最长回文子序列.md +++ b/problems/0516.最长回文子序列.md @@ -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]; +}; +``` + + + -----------------------
diff --git a/problems/0739.每日温度.md b/problems/0739.每日温度.md index 987ce27e..7472a3ae 100644 --- a/problems/0739.每日温度.md +++ b/problems/0739.每日温度.md @@ -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; +}; +``` +