Merge branch 'youngyangyang04:master' into master

This commit is contained in:
JaneyLin
2022-06-16 20:44:17 -05:00
committed by GitHub
3 changed files with 140 additions and 5 deletions

View File

@ -268,7 +268,7 @@ var permuteUnique = function (nums) {
function backtracing( used) {
if (path.length === nums.length) {
result.push(path.slice())
result.push([...path])
return
}
for (let i = 0; i < nums.length; i++) {
@ -303,7 +303,7 @@ function permuteUnique(nums: number[]): number[][] {
return resArr;
function backTracking(nums: number[], route: number[]): void {
if (route.length === nums.length) {
resArr.push(route.slice());
resArr.push([...route]);
return;
}
for (let i = 0, length = nums.length; i < length; i++) {

View File

@ -406,6 +406,63 @@ const countSubstrings = (s) => {
}
```
TypeScript
> 动态规划:
```typescript
function countSubstrings(s: string): number {
/**
dp[i][j]: [i,j]区间内的字符串是否为回文(左闭右闭)
*/
const length: number = s.length;
const dp: boolean[][] = new Array(length).fill(0)
.map(_ => new Array(length).fill(false));
let resCount: number = 0;
// 自下而上,自左向右遍历
for (let i = length - 1; i >= 0; i--) {
for (let j = i; j < length; j++) {
if (
s[i] === s[j] &&
(j - i <= 1 || dp[i + 1][j - 1] === true)
) {
dp[i][j] = true;
resCount++;
}
}
}
return resCount;
};
```
> 双指针法:
```typescript
function countSubstrings(s: string): number {
const length: number = s.length;
let resCount: number = 0;
for (let i = 0; i < length; i++) {
resCount += expandRange(s, i, i);
resCount += expandRange(s, i, i + 1);
}
return resCount;
};
function expandRange(s: string, left: number, right: number): number {
let palindromeNum: number = 0;
while (
left >= 0 && right < s.length &&
s[left] === s[right]
) {
palindromeNum++;
left--;
right++;
}
return palindromeNum;
}
```
-----------------------
<div align="center"><img src=https://code-thinking.cdn.bcebos.com/pics/01二维码一.jpg width=500> </img></div>

View File

@ -365,6 +365,84 @@ class Solution:
return res
```
JavaScript
**90.子集II**
```javascript
function subsetsWithDup(nums) {
nums.sort((a, b) => a - b);
const resArr = [];
backTraking(nums, 0, []);
return resArr;
function backTraking(nums, startIndex, route) {
resArr.push([...route]);
const helperSet = new Set();
for (let i = startIndex, length = nums.length; i < length; i++) {
if (helperSet.has(nums[i])) continue;
helperSet.add(nums[i]);
route.push(nums[i]);
backTraking(nums, i + 1, route);
route.pop();
}
}
};
```
**40. 组合总和 II**
```javascript
function combinationSum2(candidates, target) {
candidates.sort((a, b) => a - b);
const resArr = [];
backTracking(candidates, target, 0, 0, []);
return resArr;
function backTracking( candidates, target, curSum, startIndex, route ) {
if (curSum > target) return;
if (curSum === target) {
resArr.push([...route]);
return;
}
const helperSet = new Set();
for (let i = startIndex, length = candidates.length; i < length; i++) {
let tempVal = candidates[i];
if (helperSet.has(tempVal)) continue;
helperSet.add(tempVal);
route.push(tempVal);
backTracking(candidates, target, curSum + tempVal, i + 1, route);
route.pop();
}
}
};
```
**47. 全排列 II**
```javaescript
function permuteUnique(nums) {
const resArr = [];
const usedArr = [];
backTracking(nums, []);
return resArr;
function backTracking(nums, route) {
if (nums.length === route.length) {
resArr.push([...route]);
return;
}
const usedSet = new Set();
for (let i = 0, length = nums.length; i < length; i++) {
if (usedArr[i] === true || usedSet.has(nums[i])) continue;
usedSet.add(nums[i]);
route.push(nums[i]);
usedArr[i] = true;
backTracking(nums, route);
usedArr[i] = false;
route.pop();
}
}
};
```
TypeScript
**90.子集II**
@ -376,7 +454,7 @@ function subsetsWithDup(nums: number[]): number[][] {
backTraking(nums, 0, []);
return resArr;
function backTraking(nums: number[], startIndex: number, route: number[]): void {
resArr.push(route.slice());
resArr.push([...route]);
const helperSet: Set<number> = new Set();
for (let i = startIndex, length = nums.length; i < length; i++) {
if (helperSet.has(nums[i])) continue;
@ -403,7 +481,7 @@ function combinationSum2(candidates: number[], target: number): number[][] {
) {
if (curSum > target) return;
if (curSum === target) {
resArr.push(route.slice());
resArr.push([...route]);
return;
}
const helperSet: Set<number> = new Set();
@ -430,7 +508,7 @@ function permuteUnique(nums: number[]): number[][] {
return resArr;
function backTracking(nums: number[], route: number[]): void {
if (nums.length === route.length) {
resArr.push(route.slice());
resArr.push([...route]);
return;
}
const usedSet: Set<number> = new Set();