feat: leetcode 328

Author: deweyou

README.md

@@ -2,7 +2,7 @@
 
 <p align="center">
 <!-- TOPICS COUNT START -->
-<img src="https://img.shields.io/badge/-进度:348-green" alt="进度:348">
+<img src="https://img.shields.io/badge/-进度:349-green" alt="进度:349">
 <!-- TOPICS COUNT END -->
 <a href="./assets/docs/TOPICS.md"><img src="https://img.shields.io/badge/-题库目录-blue" alt="题库目录"></a>
 <a href="./assets/docs/CATEGORIES.md"><img src="https://img.shields.io/badge/-题库分类-red" alt="题库分类"></a>

assets/data/categories.json

@@ -391,6 +391,12 @@
         "path": "./problemset/delete-node-in-a-linked-list/README.md",
         "difficulty": "简单"
       },
+      {
+        "id": "328",
+        "title": "奇偶链表",
+        "path": "./problemset/odd-even-linked-list/README.md",
+        "difficulty": "中等"
+      },
       {
         "id": "432",
         "title": "全 O(1) 的数据结构",

assets/data/topics.json

@@ -2579,6 +2579,16 @@
     "url": "https://leetcode-cn.com/problems/count-of-range-sum/",
     "path": "./problemset/count-of-range-sum/README.md"
   },
+  {
+    "id": "328",
+    "title": {
+      "cn": "奇偶链表",
+      "en": "odd-even-linked-list"
+    },
+    "difficulty": "中等",
+    "url": "https://leetcode-cn.com/problems/odd-even-linked-list/",
+    "path": "./problemset/odd-even-linked-list/README.md"
+  },
   {
     "id": "342",
     "title": {

assets/docs/CATEGORIES.md

@@ -73,6 +73,7 @@
 | 203. [移除链表元素](../../problemset/remove-linked-list-elements/README.md) | 简单 |
 | 206. [反转链表](../../problemset/reverse-linked-list/README.md) | 简单 |
 | 237. [删除链表中的节点](../../problemset/delete-node-in-a-linked-list/README.md) | 简单 |
+| 328. [奇偶链表](../../problemset/odd-even-linked-list/README.md) | 中等 |
 | 432. [全 O(1) 的数据结构](../../problemset/all-one-data-structure/README.md) | 困难 |
 
 ## 滑动窗口

assets/docs/TOPICS.md

@@ -516,6 +516,8 @@
 
 [327. 区间和的个数](../../problemset/count-of-range-sum/README.md)
 
+[328. 奇偶链表](../../problemset/odd-even-linked-list/README.md)
+
 [342. 4的幂](../../problemset/power-of-four/README.md)
 
 [355. 设计推特](../../problemset/design-twitter/README.md)

problemset/odd-even-linked-list/README.md

@@ -0,0 +1,71 @@
+# 奇偶链表
+
+> 难度：中等
+>
+> https://leetcode-cn.com/problems/odd-even-linked-list/
+
+## 题目
+
+给定单链表的头节点 `head` ，将所有索引为奇数的节点和索引为偶数的节点分别组合在一起，然后返回重新排序的列表。
+
+第一个节点的索引被认为是 **奇数** ， 第二个节点的索引为 **偶数** ，以此类推。
+
+请注意，偶数组和奇数组内部的相对顺序应该与输入时保持一致。
+
+你必须在 `O(1)` 的额外空间复杂度和 `O(n)` 的时间复杂度下解决这个问题。
+
+### 示例
+
+#### 示例 1：
+
+![oddeven-linked-list](https://user-images.githubusercontent.com/54696834/165983103-1d7f9c60-e1e4-4910-9ed8-de30413ac48a.jpg)
+
+```
+输入: head = [1,2,3,4,5]
+输出: [1,3,5,2,4]
+```
+
+#### 示例 2：
+
+![oddeven2-linked-list](https://user-images.githubusercontent.com/54696834/165983115-10667613-ac82-4353-a781-e21c74e67ae5.jpg)
+
+```
+输入: head = [2,1,3,5,6,4,7]
+输出: [2,3,6,7,1,5,4]
+```
+
+## 解题
+
+```ts 
+/**
+ * 分离再拼接
+ * @desc 时间复杂度 O(N)  空间复杂度 O(1)
+ * @param head
+ * @returns
+ */
+export function oddEvenList(head: ListNode | null): ListNode | null {
+  if (!head) return null
+
+  let odd = head
+  const evenRoot = head.next
+  let even = evenRoot
+  if (even === null || even.next === null) return head
+
+  let cur: ListNode | null = even.next
+  while (cur) {
+    odd.next = cur
+    odd = odd.next
+    cur = cur.next
+
+    if (cur) {
+      even.next = cur
+      even = even.next
+      cur = cur.next
+    }
+  }
+
+  odd.next = evenRoot
+  even.next = null
+  return head
+}
+```

problemset/odd-even-linked-list/index.spec.ts

@@ -0,0 +1,23 @@
+import { describe, expect, it } from 'vitest'
+import { oddEvenList } from '.'
+import type { ListNode } from '~/utils/listNode'
+import { createListNode } from '~/utils/listNode'
+
+describe('奇偶链表', () => {
+  testCase(oddEvenList)
+})
+
+function testCase(fn: (head: ListNode | null) => ListNode | null) {
+  it.each([
+    [
+      [1, 2, 3, 4, 5],
+      [1, 3, 5, 2, 4],
+    ],
+    [
+      [2, 1, 3, 5, 6, 4, 7],
+      [2, 3, 6, 7, 1, 5, 4],
+    ],
+  ])('示例%#', (head, expected) => {
+    expect(fn(createListNode(head))).toStrictEqual(createListNode(expected))
+  })
+}

problemset/odd-even-linked-list/index.ts

@@ -0,0 +1,33 @@
+import type { ListNode } from '~/utils/listNode'
+
+/**
+ * 分离再拼接
+ * @desc 时间复杂度 O(N)  空间复杂度 O(1)
+ * @param head
+ * @returns
+ */
+export function oddEvenList(head: ListNode | null): ListNode | null {
+  if (!head) return null
+
+  let odd = head
+  const evenRoot = head.next
+  let even = evenRoot
+  if (even === null || even.next === null) return head
+
+  let cur: ListNode | null = even.next
+  while (cur) {
+    odd.next = cur
+    odd = odd.next
+    cur = cur.next
+
+    if (cur) {
+      even.next = cur
+      even = even.next
+      cur = cur.next
+    }
+  }
+
+  odd.next = evenRoot
+  even.next = null
+  return head
+}