# Swapping Nodes in a Linked List

Updated: Mar 24, 2021

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]

**Example 3:**

**Input****:** head = [1], k = 1
**Output****:** [1]

**Example 4:**

**Input****:** head = [1,2], k = 1
**Output****:** [2,1]

**Example 5:**

**Input****:** head = [1,2,3], k = 2
**Output****:** [1,2,3]

**Constraints:**

The number of nodes in the list is n.

1 <= k <= n <= 105

0 <= Node.val <= 100

**Solution:**

```
/**
* Definition for singly-linked list.
* public class ListNode {
* int val;
* ListNode next;
* ListNode() {}
* ListNode(int val) { this.val = val; }
* ListNode(int val, ListNode next) { this.val = val; this.next = next; }
* }
*/
class Solution {
public ListNode swapNodes(ListNode head, int k) {
ListNode p1=null;
ListNode p2=head;
ListNode result = head;
while(--k>0)
{
head=head.next;
}
p1=head;
while(head.next!=null)
{
p2=p2.next;
head=head.next;
}
int temp = p2.val;
p2.val=p1.val;
p1.val=temp;
return result;
}
}
```