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https://github.com/youngyangyang04/leetcode-master.git
synced 2025-07-11 04:54:51 +08:00
Merge branch 'youngyangyang04:master' into master
This commit is contained in:
@ -246,7 +246,35 @@ var levelOrder = function(root) {
|
||||
|
||||
```
|
||||
|
||||
TypeScript:
|
||||
|
||||
```typescript
|
||||
function levelOrder(root: TreeNode | null): number[][] {
|
||||
let helperQueue: TreeNode[] = [];
|
||||
let res: number[][] = [];
|
||||
let tempArr: number[] = [];
|
||||
if (root !== null) helperQueue.push(root);
|
||||
let curNode: TreeNode;
|
||||
while (helperQueue.length > 0) {
|
||||
for (let i = 0, length = helperQueue.length; i < length; i++) {
|
||||
curNode = helperQueue.shift()!;
|
||||
tempArr.push(curNode.val);
|
||||
if (curNode.left !== null) {
|
||||
helperQueue.push(curNode.left);
|
||||
}
|
||||
if (curNode.right !== null) {
|
||||
helperQueue.push(curNode.right);
|
||||
}
|
||||
}
|
||||
res.push(tempArr);
|
||||
tempArr = [];
|
||||
}
|
||||
return res;
|
||||
};
|
||||
```
|
||||
|
||||
Swift:
|
||||
|
||||
```swift
|
||||
func levelOrder(_ root: TreeNode?) -> [[Int]] {
|
||||
var res = [[Int]]()
|
||||
@ -454,7 +482,31 @@ var levelOrderBottom = function(root) {
|
||||
};
|
||||
```
|
||||
|
||||
TypeScript:
|
||||
|
||||
```typescript
|
||||
function levelOrderBottom(root: TreeNode | null): number[][] {
|
||||
let helperQueue: TreeNode[] = [];
|
||||
let resArr: number[][] = [];
|
||||
let tempArr: number[] = [];
|
||||
let tempNode: TreeNode;
|
||||
if (root !== null) helperQueue.push(root);
|
||||
while (helperQueue.length > 0) {
|
||||
for (let i = 0, length = helperQueue.length; i < length; i++) {
|
||||
tempNode = helperQueue.shift()!;
|
||||
tempArr.push(tempNode.val);
|
||||
if (tempNode.left !== null) helperQueue.push(tempNode.left);
|
||||
if (tempNode.right !== null) helperQueue.push(tempNode.right);
|
||||
}
|
||||
resArr.push(tempArr);
|
||||
tempArr = [];
|
||||
}
|
||||
return resArr.reverse();
|
||||
};
|
||||
```
|
||||
|
||||
Swift:
|
||||
|
||||
```swift
|
||||
func levelOrderBottom(_ root: TreeNode?) -> [[Int]] {
|
||||
var res = [[Int]]()
|
||||
@ -657,7 +709,28 @@ var rightSideView = function(root) {
|
||||
};
|
||||
```
|
||||
|
||||
TypeScript:
|
||||
|
||||
```typescript
|
||||
function rightSideView(root: TreeNode | null): number[] {
|
||||
let helperQueue: TreeNode[] = [];
|
||||
let resArr: number[] = [];
|
||||
let tempNode: TreeNode;
|
||||
if (root !== null) helperQueue.push(root);
|
||||
while (helperQueue.length > 0) {
|
||||
for (let i = 0, length = helperQueue.length; i < length; i++) {
|
||||
tempNode = helperQueue.shift()!;
|
||||
if (i === length - 1) resArr.push(tempNode.val);
|
||||
if (tempNode.left !== null) helperQueue.push(tempNode.left);
|
||||
if (tempNode.right !== null) helperQueue.push(tempNode.right);
|
||||
}
|
||||
}
|
||||
return resArr;
|
||||
};
|
||||
```
|
||||
|
||||
Swift:
|
||||
|
||||
```swift
|
||||
func rightSideView(_ root: TreeNode?) -> [Int] {
|
||||
var res = [Int]()
|
||||
@ -868,7 +941,32 @@ var averageOfLevels = function(root) {
|
||||
};
|
||||
```
|
||||
|
||||
TypeScript:
|
||||
|
||||
```typescript
|
||||
function averageOfLevels(root: TreeNode | null): number[] {
|
||||
let helperQueue: TreeNode[] = [];
|
||||
let resArr: number[] = [];
|
||||
let total: number = 0;
|
||||
let tempNode: TreeNode;
|
||||
if (root !== null) helperQueue.push(root);
|
||||
while (helperQueue.length > 0) {
|
||||
let length = helperQueue.length;
|
||||
for (let i = 0; i < length; i++) {
|
||||
tempNode = helperQueue.shift()!;
|
||||
total += tempNode.val;
|
||||
if (tempNode.left) helperQueue.push(tempNode.left);
|
||||
if (tempNode.right) helperQueue.push(tempNode.right);
|
||||
}
|
||||
resArr.push(total / length);
|
||||
total = 0;
|
||||
}
|
||||
return resArr;
|
||||
};
|
||||
```
|
||||
|
||||
Swift:
|
||||
|
||||
```swift
|
||||
func averageOfLevels(_ root: TreeNode?) -> [Double] {
|
||||
var res = [Double]()
|
||||
@ -1092,7 +1190,30 @@ var levelOrder = function(root) {
|
||||
};
|
||||
```
|
||||
|
||||
TypeScript:
|
||||
|
||||
```typescript
|
||||
function levelOrder(root: Node | null): number[][] {
|
||||
let helperQueue: Node[] = [];
|
||||
let resArr: number[][] = [];
|
||||
let tempArr: number[] = [];
|
||||
if (root !== null) helperQueue.push(root);
|
||||
let curNode: Node;
|
||||
while (helperQueue.length > 0) {
|
||||
for (let i = 0, length = helperQueue.length; i < length; i++) {
|
||||
curNode = helperQueue.shift()!;
|
||||
tempArr.push(curNode.val);
|
||||
helperQueue.push(...curNode.children);
|
||||
}
|
||||
resArr.push(tempArr);
|
||||
tempArr = [];
|
||||
}
|
||||
return resArr;
|
||||
};
|
||||
```
|
||||
|
||||
Swift:
|
||||
|
||||
```swift
|
||||
func levelOrder(_ root: Node?) -> [[Int]] {
|
||||
var res = [[Int]]()
|
||||
@ -1272,7 +1393,34 @@ var largestValues = function(root) {
|
||||
};
|
||||
```
|
||||
|
||||
TypeScript:
|
||||
|
||||
```typescript
|
||||
function largestValues(root: TreeNode | null): number[] {
|
||||
let helperQueue: TreeNode[] = [];
|
||||
let resArr: number[] = [];
|
||||
let tempNode: TreeNode;
|
||||
let max: number = 0;
|
||||
if (root !== null) helperQueue.push(root);
|
||||
while (helperQueue.length > 0) {
|
||||
for (let i = 0, length = helperQueue.length; i < length; i++) {
|
||||
tempNode = helperQueue.shift()!;
|
||||
if (i === 0) {
|
||||
max = tempNode.val;
|
||||
} else {
|
||||
max = max > tempNode.val ? max : tempNode.val;
|
||||
}
|
||||
if (tempNode.left) helperQueue.push(tempNode.left);
|
||||
if (tempNode.right) helperQueue.push(tempNode.right);
|
||||
}
|
||||
resArr.push(max);
|
||||
}
|
||||
return resArr;
|
||||
};
|
||||
```
|
||||
|
||||
Swift:
|
||||
|
||||
```swift
|
||||
func largestValues(_ root: TreeNode?) -> [Int] {
|
||||
var res = [Int]()
|
||||
@ -1463,6 +1611,31 @@ var connect = function(root) {
|
||||
};
|
||||
|
||||
```
|
||||
TypeScript:
|
||||
|
||||
```typescript
|
||||
function connect(root: Node | null): Node | null {
|
||||
let helperQueue: Node[] = [];
|
||||
let preNode: Node, curNode: Node;
|
||||
if (root !== null) helperQueue.push(root);
|
||||
while (helperQueue.length > 0) {
|
||||
for (let i = 0, length = helperQueue.length; i < length; i++) {
|
||||
if (i === 0) {
|
||||
preNode = helperQueue.shift()!;
|
||||
} else {
|
||||
curNode = helperQueue.shift()!;
|
||||
preNode.next = curNode;
|
||||
preNode = curNode;
|
||||
}
|
||||
if (preNode.left) helperQueue.push(preNode.left);
|
||||
if (preNode.right) helperQueue.push(preNode.right);
|
||||
}
|
||||
preNode.next = null;
|
||||
}
|
||||
return root;
|
||||
};
|
||||
```
|
||||
|
||||
go:
|
||||
|
||||
```GO
|
||||
@ -1689,6 +1862,31 @@ var connect = function(root) {
|
||||
return root;
|
||||
};
|
||||
```
|
||||
TypeScript:
|
||||
|
||||
```typescript
|
||||
function connect(root: Node | null): Node | null {
|
||||
let helperQueue: Node[] = [];
|
||||
let preNode: Node, curNode: Node;
|
||||
if (root !== null) helperQueue.push(root);
|
||||
while (helperQueue.length > 0) {
|
||||
for (let i = 0, length = helperQueue.length; i < length; i++) {
|
||||
if (i === 0) {
|
||||
preNode = helperQueue.shift()!;
|
||||
} else {
|
||||
curNode = helperQueue.shift()!;
|
||||
preNode.next = curNode;
|
||||
preNode = curNode;
|
||||
}
|
||||
if (preNode.left) helperQueue.push(preNode.left);
|
||||
if (preNode.right) helperQueue.push(preNode.right);
|
||||
}
|
||||
preNode.next = null;
|
||||
}
|
||||
return root;
|
||||
};
|
||||
```
|
||||
|
||||
go:
|
||||
|
||||
```GO
|
||||
@ -1933,7 +2131,28 @@ var maxDepth = function(root) {
|
||||
};
|
||||
```
|
||||
|
||||
TypeScript:
|
||||
|
||||
```typescript
|
||||
function maxDepth(root: TreeNode | null): number {
|
||||
let helperQueue: TreeNode[] = [];
|
||||
let resDepth: number = 0;
|
||||
let tempNode: TreeNode;
|
||||
if (root !== null) helperQueue.push(root);
|
||||
while (helperQueue.length > 0) {
|
||||
resDepth++;
|
||||
for (let i = 0, length = helperQueue.length; i < length; i++) {
|
||||
tempNode = helperQueue.shift()!;
|
||||
if (tempNode.left) helperQueue.push(tempNode.left);
|
||||
if (tempNode.right) helperQueue.push(tempNode.right);
|
||||
}
|
||||
}
|
||||
return resDepth;
|
||||
};
|
||||
```
|
||||
|
||||
Swift:
|
||||
|
||||
```swift
|
||||
func maxDepth(_ root: TreeNode?) -> Int {
|
||||
guard let root = root else {
|
||||
@ -2130,7 +2349,29 @@ var minDepth = function(root) {
|
||||
};
|
||||
```
|
||||
|
||||
TypeScript:
|
||||
|
||||
```typescript
|
||||
function minDepth(root: TreeNode | null): number {
|
||||
let helperQueue: TreeNode[] = [];
|
||||
let resMin: number = 0;
|
||||
let tempNode: TreeNode;
|
||||
if (root !== null) helperQueue.push(root);
|
||||
while (helperQueue.length > 0) {
|
||||
resMin++;
|
||||
for (let i = 0, length = helperQueue.length; i < length; i++) {
|
||||
tempNode = helperQueue.shift()!;
|
||||
if (tempNode.left === null && tempNode.right === null) return resMin;
|
||||
if (tempNode.left !== null) helperQueue.push(tempNode.left);
|
||||
if (tempNode.right !== null) helperQueue.push(tempNode.right);
|
||||
}
|
||||
}
|
||||
return resMin;
|
||||
};
|
||||
```
|
||||
|
||||
Swift:
|
||||
|
||||
```swift
|
||||
func minDepth(_ root: TreeNode?) -> Int {
|
||||
guard let root = root else {
|
||||
|
@ -531,82 +531,63 @@ class solution:
|
||||
```go
|
||||
//递归法
|
||||
/**
|
||||
* definition for a binary tree node.
|
||||
* type treenode struct {
|
||||
* val int
|
||||
* left *treenode
|
||||
* right *treenode
|
||||
* Definition for a binary tree node.
|
||||
* type TreeNode struct {
|
||||
* Val int
|
||||
* Left *TreeNode
|
||||
* Right *TreeNode
|
||||
* }
|
||||
*/
|
||||
func haspathsum(root *treenode, targetsum int) bool {
|
||||
var flage bool //找没找到的标志
|
||||
if root==nil{
|
||||
return flage
|
||||
func hasPathSum(root *TreeNode, targetSum int) bool {
|
||||
if root == nil {
|
||||
return false
|
||||
}
|
||||
pathsum(root,0,targetsum,&flage)
|
||||
return flage
|
||||
}
|
||||
func pathsum(root *treenode, sum int,targetsum int,flage *bool){
|
||||
sum+=root.val
|
||||
if root.left==nil&&root.right==nil&&sum==targetsum{
|
||||
*flage=true
|
||||
return
|
||||
}
|
||||
if root.left!=nil&&!(*flage){//左节点不为空且还没找到
|
||||
pathsum(root.left,sum,targetsum,flage)
|
||||
}
|
||||
if root.right!=nil&&!(*flage){//右节点不为空且没找到
|
||||
pathsum(root.right,sum,targetsum,flage)
|
||||
|
||||
targetSum -= root.Val // 将targetSum在遍历每层的时候都减去本层节点的值
|
||||
if root.Left == nil && root.Right == nil && targetSum == 0 { // 如果剩余的targetSum为0, 则正好就是符合的结果
|
||||
return true
|
||||
}
|
||||
return hasPathSum(root.Left, targetSum) || hasPathSum(root.Right, targetSum) // 否则递归找
|
||||
}
|
||||
```
|
||||
|
||||
113 递归法
|
||||
113. 路径总和 II
|
||||
|
||||
```go
|
||||
/**
|
||||
* definition for a binary tree node.
|
||||
* type treenode struct {
|
||||
* val int
|
||||
* left *treenode
|
||||
* right *treenode
|
||||
* Definition for a binary tree node.
|
||||
* type TreeNode struct {
|
||||
* Val int
|
||||
* Left *TreeNode
|
||||
* Right *TreeNode
|
||||
* }
|
||||
*/
|
||||
func pathsum(root *treenode, targetsum int) [][]int {
|
||||
var result [][]int//最终结果
|
||||
if root==nil{
|
||||
return result
|
||||
}
|
||||
var sumnodes []int//经过路径的节点集合
|
||||
haspathsum(root,&sumnodes,targetsum,&result)
|
||||
func pathSum(root *TreeNode, targetSum int) [][]int {
|
||||
result := make([][]int, 0)
|
||||
traverse(root, &result, new([]int), targetSum)
|
||||
return result
|
||||
}
|
||||
func haspathsum(root *treenode,sumnodes *[]int,targetsum int,result *[][]int){
|
||||
*sumnodes=append(*sumnodes,root.val)
|
||||
if root.left==nil&&root.right==nil{//叶子节点
|
||||
fmt.println(*sumnodes)
|
||||
var sum int
|
||||
var number int
|
||||
for k,v:=range *sumnodes{//求该路径节点的和
|
||||
sum+=v
|
||||
number=k
|
||||
}
|
||||
tempnodes:=make([]int,number+1)//新的nodes接受指针里的值,防止最终指针里的值发生变动,导致最后的结果都是最后一个sumnodes的值
|
||||
for k,v:=range *sumnodes{
|
||||
tempnodes[k]=v
|
||||
}
|
||||
if sum==targetsum{
|
||||
*result=append(*result,tempnodes)
|
||||
}
|
||||
|
||||
func traverse(node *TreeNode, result *[][]int, currPath *[]int, targetSum int) {
|
||||
if node == nil { // 这个判空也可以挪到递归遍历左右子树时去判断
|
||||
return
|
||||
}
|
||||
if root.left!=nil{
|
||||
haspathsum(root.left,sumnodes,targetsum,result)
|
||||
*sumnodes=(*sumnodes)[:len(*sumnodes)-1]//回溯
|
||||
}
|
||||
if root.right!=nil{
|
||||
haspathsum(root.right,sumnodes,targetsum,result)
|
||||
*sumnodes=(*sumnodes)[:len(*sumnodes)-1]//回溯
|
||||
|
||||
targetSum -= node.Val // 将targetSum在遍历每层的时候都减去本层节点的值
|
||||
*currPath = append(*currPath, node.Val) // 把当前节点放到路径记录里
|
||||
|
||||
if node.Left == nil && node.Right == nil && targetSum == 0 { // 如果剩余的targetSum为0, 则正好就是符合的结果
|
||||
// 不能直接将currPath放到result里面, 因为currPath是共享的, 每次遍历子树时都会被修改
|
||||
pathCopy := make([]int, len(*currPath))
|
||||
for i, element := range *currPath {
|
||||
pathCopy[i] = element
|
||||
}
|
||||
*result = append(*result, pathCopy) // 将副本放到结果集里
|
||||
}
|
||||
|
||||
traverse(node.Left, result, currPath, targetSum)
|
||||
traverse(node.Right, result, currPath, targetSum)
|
||||
*currPath = (*currPath)[:len(*currPath)-1] // 当前节点遍历完成, 从路径记录里删除掉
|
||||
}
|
||||
```
|
||||
|
||||
|
@ -210,6 +210,45 @@ class Solution {
|
||||
}
|
||||
```
|
||||
|
||||
二维数组版本(易于理解):
|
||||
```Java
|
||||
class Solution {
|
||||
public boolean canPartition(int[] nums) {
|
||||
int sum = 0;
|
||||
for (int i = 0; i < nums.length; i++) {
|
||||
sum += nums[i];
|
||||
}
|
||||
|
||||
if (sum % 2 == 1)
|
||||
return false;
|
||||
int target = sum / 2;
|
||||
|
||||
//dp[i][j]代表可装物品为0-i,背包容量为j的情况下,背包内容量的最大价值
|
||||
int[][] dp = new int[nums.length][target + 1];
|
||||
|
||||
//初始化,dp[0][j]的最大价值nums[0](if j > weight[i])
|
||||
//dp[i][0]均为0,不用初始化
|
||||
for (int j = nums[0]; j <= target; j++) {
|
||||
dp[0][j] = nums[0];
|
||||
}
|
||||
|
||||
//遍历物品,遍历背包
|
||||
//递推公式:
|
||||
for (int i = 1; i < nums.length; i++) {
|
||||
for (int j = 0; j <= target; j++) {
|
||||
//背包容量可以容纳nums[i]
|
||||
if (j >= nums[i]) {
|
||||
dp[i][j] = Math.max(dp[i - 1][j], dp[i - 1][j - nums[i]] + nums[i]);
|
||||
} else {
|
||||
dp[i][j] = dp[i - 1][j];
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
return dp[nums.length - 1][target] == target;
|
||||
}
|
||||
}
|
||||
```
|
||||
Python:
|
||||
```python
|
||||
class Solution:
|
||||
|
@ -153,6 +153,8 @@ public:
|
||||
|
||||
|
||||
Java:
|
||||
|
||||
一维数组版本
|
||||
```Java
|
||||
class Solution {
|
||||
public int lastStoneWeightII(int[] stones) {
|
||||
@ -173,6 +175,41 @@ class Solution {
|
||||
return sum - 2 * dp[target];
|
||||
}
|
||||
}
|
||||
```
|
||||
二维数组版本(便于理解)
|
||||
```Java
|
||||
class Solution {
|
||||
public int lastStoneWeightII(int[] stones) {
|
||||
int sum = 0;
|
||||
for (int s : stones) {
|
||||
sum += s;
|
||||
}
|
||||
|
||||
int target = sum / 2;
|
||||
//初始化,dp[i][j]为可以放0-i物品,背包容量为j的情况下背包中的最大价值
|
||||
int[][] dp = new int[stones.length][target + 1];
|
||||
//dp[i][0]默认初始化为0
|
||||
//dp[0][j]取决于stones[0]
|
||||
for (int j = stones[0]; j <= target; j++) {
|
||||
dp[0][j] = stones[0];
|
||||
}
|
||||
|
||||
for (int i = 1; i < stones.length; i++) {
|
||||
for (int j = 1; j <= target; j++) {//注意是等于
|
||||
if (j >= stones[i]) {
|
||||
//不放:dp[i - 1][j] 放:dp[i - 1][j - stones[i]] + stones[i]
|
||||
dp[i][j] = Math.max(dp[i - 1][j], dp[i - 1][j - stones[i]] + stones[i]);
|
||||
} else {
|
||||
dp[i][j] = dp[i - 1][j];
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
System.out.println(dp[stones.length - 1][target]);
|
||||
return (sum - dp[stones.length - 1][target]) - dp[stones.length - 1][target];
|
||||
}
|
||||
}
|
||||
|
||||
```
|
||||
|
||||
Python:
|
||||
|
@ -522,7 +522,75 @@ var postorderTraversal = function(root, res = []) {
|
||||
|
||||
```
|
||||
|
||||
TypeScript:
|
||||
|
||||
```typescript
|
||||
// 前序遍历(迭代法)
|
||||
function preorderTraversal(root: TreeNode | null): number[] {
|
||||
let helperStack: (TreeNode | null)[] = [];
|
||||
let res: number[] = [];
|
||||
let curNode: TreeNode | null;
|
||||
if (root === null) return res;
|
||||
helperStack.push(root);
|
||||
while (helperStack.length > 0) {
|
||||
curNode = helperStack.pop()!;
|
||||
if (curNode !== null) {
|
||||
if (curNode.right !== null) helperStack.push(curNode.right);
|
||||
helperStack.push(curNode);
|
||||
helperStack.push(null);
|
||||
if (curNode.left !== null) helperStack.push(curNode.left);
|
||||
} else {
|
||||
curNode = helperStack.pop()!;
|
||||
res.push(curNode.val);
|
||||
}
|
||||
}
|
||||
return res;
|
||||
};
|
||||
|
||||
// 中序遍历(迭代法)
|
||||
function inorderTraversal(root: TreeNode | null): number[] {
|
||||
let helperStack: (TreeNode | null)[] = [];
|
||||
let res: number[] = [];
|
||||
let curNode: TreeNode | null;
|
||||
if (root === null) return res;
|
||||
helperStack.push(root);
|
||||
while (helperStack.length > 0) {
|
||||
curNode = helperStack.pop()!;
|
||||
if (curNode !== null) {
|
||||
if (curNode.right !== null) helperStack.push(curNode.right);
|
||||
helperStack.push(curNode);
|
||||
helperStack.push(null);
|
||||
if (curNode.left !== null) helperStack.push(curNode.left);
|
||||
} else {
|
||||
curNode = helperStack.pop()!;
|
||||
res.push(curNode.val);
|
||||
}
|
||||
}
|
||||
return res;
|
||||
};
|
||||
|
||||
// 后序遍历(迭代法)
|
||||
function postorderTraversal(root: TreeNode | null): number[] {
|
||||
let helperStack: (TreeNode | null)[] = [];
|
||||
let res: number[] = [];
|
||||
let curNode: TreeNode | null;
|
||||
if (root === null) return res;
|
||||
helperStack.push(root);
|
||||
while (helperStack.length > 0) {
|
||||
curNode = helperStack.pop()!;
|
||||
if (curNode !== null) {
|
||||
if (curNode.right !== null) helperStack.push(curNode.right);
|
||||
helperStack.push(curNode);
|
||||
helperStack.push(null);
|
||||
if (curNode.left !== null) helperStack.push(curNode.left);
|
||||
} else {
|
||||
curNode = helperStack.pop()!;
|
||||
res.push(curNode.val);
|
||||
}
|
||||
}
|
||||
return res;
|
||||
};
|
||||
```
|
||||
|
||||
-----------------------
|
||||
<div align="center"><img src=https://code-thinking.cdn.bcebos.com/pics/01二维码一.jpg width=500> </img></div>
|
||||
|
Reference in New Issue
Block a user