update: 143

Author: hijiangtao

README.md

@@ -90,6 +90,7 @@ This is the solutions collection of my LeetCode submissions, most of them are pr
 | 136 | [Single Number](https://leetcode.com/problems/single-number/) | [JavaScript](./src/single-number/res.js) | Easy |
 | 137 | [Single Number II](https://leetcode.com/problems/single-number-ii/) | [JavaScript](./src/single-number-ii/res.js) | Medium |
 | 139 | [word-break](https://leetcode.com/problems/word-break/) | [TypeScript](./src/word-break/res.ts) | Medium |
+| 143 | [reorder-list](https://leetcode.com/problems/reorder-list/) | [TypeScript](./src/reorder-list/res.ts) | Medium |
 | 148 | [sort-list](https://leetcode.com/problems/sort-list/) | [TypeScript](./src/sort-list/res.ts) | Medium |
 | 151 | [Reverse Words in a String](https://leetcode.com/problems/reverse-words-in-a-string/) | [JavaScript](./src/reverse-words-in-a-string/res.js) | Medium |
 | 152 | [Maximum Product Subarray](https://leetcode.com/problems/maximum-product-subarray/) | [JavaScript](./src/maximum-product-subarray/res.js) | Medium |

src/reorder-list/res.ts

@@ -0,0 +1,35 @@
+/**
+* Definition for singly-linked list.
+* class ListNode {
+* val: number
+* next: ListNode | null
+* constructor(val?: number, next?: ListNode | null) {
+* this.val = (val===undefined ? 0 : val)
+* this.next = (next===undefined ? null : next)
+* }
+* }
+*/
+
+/**
+Do not return anything, modify head in-place instead.
+*/
+function reorderList(head: ListNode | null): void {
+if (!head?.next?.next) {
+return ;
+}
+
+let prevTailNode = head;
+let tailNode = head;
+while (tailNode.next) {
+prevTailNode = tailNode;
+tailNode = tailNode.next;
+}
+
+const restNodes = head.next;
+prevTailNode.next = null;
+head.next = tailNode;
+tailNode.next = restNodes;
+reorderList(restNodes);
+
+return ;
+};