public class Solution
extends Object
1721 - Swapping Nodes in a Linked List\.
Medium
You are given the `head` of a linked list, and an integer `k`.
Return _the head of the linked list after **swapping** the values of the_ kth _node from the beginning and the_ kth _node from the end (the list is **1-indexed** )._
**Example 1:**
**Input:** head = [1,2,3,4,5], k = 2
**Output:** [1,4,3,2,5]
**Example 2:**
**Input:** head = [7,9,6,6,7,8,3,0,9,5], k = 5
**Output:** [7,9,6,6,8,7,3,0,9,5]
**Constraints:**
* The number of nodes in the list is `n`.
* 1 <= k <= n <= 105
* `0 <= Node.val <= 100`