24. Swap Nodes in Pairs
24. Swap Nodes in Pairs
题目
Given a linked list, swap every two adjacent nodes and return its head. You must solve the problem without modifying the values in the list's nodes (i.e., only nodes themselves may be changed.)
Example 1:
![](https://assets.leetcode.com/uploads/2020/10/03/swap_ex1.jpg)
Input: head = [1,2,3,4]
Output: [2,1,4,3]
Example 2:
Input: head = []
Output: []
Example 3:
Input: head = [1]
Output: [1]
Constraints:
- The number of nodes in the list is in the range
[0, 100]
. 0 <= Node.val <= 100
题目大意
两两相邻的元素,翻转链表
解题思路
按照题意做即可。
代码
/**
* @param {ListNode} head
* @return {ListNode}
*/
var swapPairs = function (head) {
let res = new ListNode(0, head);
let prev = res;
while (prev.next && prev.next.next) {
let cur = prev.next;
let temp = cur.next;
cur.next = temp.next;
prev.next = temp;
temp.next = cur;
prev = cur;
}
return res.next;
};
相关题目
相关题目
- [25. K 个一组翻转链表](./0025.md)
- [1721. 交换链表中的节点](https://leetcode.com/problems/swapping-nodes-in-a-linked-list)