|
| 1 | + |
| 2 | +>仰望星空的人,不应该被嘲笑 |
| 3 | + |
| 4 | +## 题目描述 |
| 5 | + |
| 6 | +给定一个链表,两两交换其中相邻的节点,并返回交换后的链表。 |
| 7 | + |
| 8 | +你不能只是单纯的改变节点内部的值,而是需要实际的进行节点交换。 |
| 9 | + |
| 10 | + |
| 11 | + |
| 12 | +示例: |
| 13 | + |
| 14 | +```javascript |
| 15 | +给定 1->2->3->4, 你应该返回 2->1->4->3. |
| 16 | +``` |
| 17 | + |
| 18 | +来源:力扣(LeetCode) |
| 19 | +链接:https://leetcode-cn.com/problems/swap-nodes-in-pairs |
| 20 | +著作权归领扣网络所有。商业转载请联系官方授权,非商业转载请注明出处。 |
| 21 | + |
| 22 | +## 解题思路 |
| 23 | + |
| 24 | +**非递归解法** |
| 25 | + |
| 26 | +```javascript |
| 27 | +/** |
| 28 | + * Definition for singly-linked list. |
| 29 | + * function ListNode(val) { |
| 30 | + * this.val = val; |
| 31 | + * this.next = null; |
| 32 | + * } |
| 33 | + */ |
| 34 | +/** |
| 35 | + * @param {ListNode} head |
| 36 | + * @return {ListNode} |
| 37 | + */ |
| 38 | +var swapPairs = function(head) { |
| 39 | + if(head == null || head.next == null) return head; |
| 40 | + let hummyHead = new ListNode(); // 虚拟节点 |
| 41 | + hummyHead.next = head; |
| 42 | + let p = hummyHead; |
| 43 | + let node1,node2; // 当前要交换的两个节点 |
| 44 | + while((node1 = p.next) && (node2 = p.next.next)){ |
| 45 | + // 进行交换操作 |
| 46 | + node1.next = node2.next; |
| 47 | + node2.next = node1; |
| 48 | + // 将链表串起来 |
| 49 | + p.next = node2; |
| 50 | + p = node1; |
| 51 | + } |
| 52 | + return hummyHead.next; |
| 53 | +}; |
| 54 | +``` |
| 55 | + |
| 56 | +**递归解法** |
| 57 | + |
| 58 | +```javascript |
| 59 | +/** |
| 60 | + * Definition for singly-linked list. |
| 61 | + * function ListNode(val) { |
| 62 | + * this.val = val; |
| 63 | + * this.next = null; |
| 64 | + * } |
| 65 | + */ |
| 66 | +/** |
| 67 | + * @param {ListNode} head |
| 68 | + * @return {ListNode} |
| 69 | + */ |
| 70 | +var swapPairs = function (head) { |
| 71 | + if (!head || !head.next) return head; |
| 72 | + let node1 = head, node2 = head.next; |
| 73 | + node1.next = swapPairs(node2.next); |
| 74 | + node2.next = node1; |
| 75 | + return node2; |
| 76 | +}; |
| 77 | +``` |
| 78 | + |
| 79 | + |
| 80 | +## 最后 |
| 81 | +文章产出不易,还望各位小伙伴们支持一波! |
| 82 | + |
| 83 | +往期精选: |
| 84 | + |
| 85 | +<a href="https://github.com/Chocolate1999/Front-end-learning-to-organize-notes">小狮子前端の笔记仓库</a> |
| 86 | + |
| 87 | +<a href="https://github.com/Chocolate1999/leetcode-javascript">leetcode-javascript:LeetCode 力扣的 JavaScript 解题仓库,前端刷题路线(思维导图)</a> |
| 88 | + |
| 89 | +小伙伴们可以在Issues中提交自己的解题代码,🤝 欢迎Contributing,可打卡刷题,Give a ⭐️ if this project helped you! |
| 90 | + |
| 91 | + |
| 92 | +<a href="https://yangchaoyi.vip/">访问超逸の博客</a>,方便小伙伴阅读玩耍~ |
| 93 | + |
| 94 | + |
| 95 | + |
| 96 | +```javascript |
| 97 | +学如逆水行舟,不进则退 |
| 98 | +``` |
| 99 | + |
| 100 | + |
| 101 | + |
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