# 两数之和
给你链表的头节点 head
和一个整数 k
。
交换 链表正数第 k
个节点和倒数第 k
个节点的值后,返回链表的头节点(链表 从 1 开始索引)。
示例 1:
输入:head = [1,2,3,4,5], k = 2 输出:[1,4,3,2,5]
示例 2:
输入:head = [7,9,6,6,7,8,3,0,9,5], k = 5 输出:[7,9,6,6,8,7,3,0,9,5]
示例 3:
输入:head = [1], k = 1 输出:[1]
示例 4:
输入:head = [1,2], k = 1 输出:[2,1]
示例 5:
输入:head = [1,2,3], k = 2 输出:[1,2,3]
提示:
n
1 <= k <= n <= 105
0 <= Node.val <= 100
以下错误的选项是?
## aop ### before ```cpp ``` ### after ```cpp ``` ## 答案 ```cpp ``` ## 选项 ### A ```cpp ``` ### B ```cpp ``` ### C ```cpp ```