demo

``` > function longestPalindrome(str) { let arr = [] let fun = function (s) { for (let i = 0; i < s.length; i++) { let v = s[i] //查找...

### const removeDup = (s) => { let stack = [] for (let i = 0; i < s.length; i++) { let prev = stack.pop() if (prev !== s[i]) {...

``` let lengthOfLongestSubstring(str) { //对原数组进行判断，是否在arr里 如果在就将arr字符串之前的全部去除，不在就直接push，最后判断长度 let arr = [] let length = 0 for (let m of str) { if (arr.includes(m)) { let index = arr.indexOf(m) arr.splice(0, index +...

### //使用冒泡排序 const countingSort = (arr, k) => { for (let i = 0; i < arr.length; i++) { for (let j = i + 1; j < arr.length; j++)...

``` function quickSort(arr) { if (arr.length

### static firstUniqChar(s) { let map = {} for (let c of s) { if (map[c]) { map[c] = map[c] + 1 } else { map[c] = 1 } }...

### const setArr = arr => { // 利用对象属性唯一性 let obj = {} for (let i = 0; i < arr.length; i++) { if (obj[arr[i]]) { arr.splice(i, 1); i-- }...

``` function threeSum(nums) { let arr = [] nums.sort((a, b) => (a - b)) for (let i = 0; i < nums.length - 2; i++) { let v1 = nums[i]...

``` function twoSum(nums, target) { let map = {} let arr = [] arr.forEach((item, index) => { map[item] = index }) for (let i = 0; i < nums.length; i++)...

``` ### const comfiles = (arr, val) => { let sta = -1, end = -1; let obj = {} arr.forEach((item, index) => { if (item === val) { if...