Solution: Swapping Nodes in a Linked List

Statement▼

Given the head of a linked list and an integer, k, return the head of the linked list after swapping the values of the $k^{th}$ node from the beginning and the $k^{th}$ node from the end of the linked list.

Note: We’ll number the nodes of the linked list starting from $1$ to $n$ .

Constraints:

The linked list will have n number of nodes.
$1 \leq$ k $\leq$ n $\leq 500$
$-5000 \leq$ Node.value $\leq 5000$

Solution

Swapping the $k^{th}$ node from the start and the $k^{th}$ node from the end in a singly linked list can be done using different methods. We’ll explore the three-pass, two-pass, and one-pass approaches in detail.