Anran

```javascript var mergeTwoLists = function (l1, l2) { let prev = new ListNode(); let p1 = l1, p2 = l2; let current = prev; while (p1 && p2) { if...

```javascript var addTwoNumbers = function (l1, l2) { let dump = new ListNode(); let p1 = l1, p2 = l2, current = dump; // 进位标识 let curry = 0; while...

```javascript var twoSum = function(nums, target) { let tmpMap = new Map(); for(let index = 0;index < nums.length; index ++) { let toSearch = target - nums[index]; if(tmpMap.has(toSearch)) { return...

```javascript var levelOrderBottom = function(root) { if(!root) return []; let res = []; let queue = [root]; while(queue.length) { let len = queue.length; res.unshift([]); for(let i = 0; i <...

```javascript var removeDuplicates = function(S) { let len = S.length; if(len === 0) return ''; let stack = [S[0]]; for(let i = 1; i < len; i++) { if(stack[stack.length -...

```javascript var Solution = function(nums) { this.arr = nums; }; Solution.prototype.reset = function() { return this.arr; }; Solution.prototype.shuffle = function() { // 拷贝数组 let nums = this.arr.slice(); let len =...

```javascript var isValid = function (s) { let map = new Map(); map.set('}', '{'); map.set(')', '('); map.set(']', '['); let right = ['}', ')', ']']; let tmpStack = new Array(); for...

```javascript function flat(arr) { while(arr.some(ietm => Array.isArray(ietm))) { arr = [].concat([...arr]); } return arr; } ```

```javascript var preorderTraversal = function (root) { if (!root) return []; let stack = [root]; let res = []; while (stack.length) { let node = stack.pop(); res.push(node.val); if (node.right) {...

```javascript var middleNode = function(head) { // 定义快慢指针 let slow = fast = head; while(fast && fast.next) { slow = slow.next; fast = fast.next.next; } return slow; }; ```