Reversing a Singly Linked List in Place

Problem

Given a singly linked list, write a function to reverse the linked list in place.
Input: 1 -> 2 -> 3 -> 4 -> 5
Output: 5 -> 4 -> 3 -> 2 -> 1

Solution

This solution is in JavaScript. Our A.I. can create solutions in multiple languages.

kayakane

// Solution:
// The optimal solution is to use a while loop to iterate through the linked list.
// The while loop will continue until the current node is null.
// The while loop will set the current node's next to the previous node.
// The while loop will then set the previous node to the current node.
// The while loop will then set the current node to the next node.
// The while loop will then set the next node to the current node's next.
// The while loop will then set the head to the previous node.

function reverseLinkedList(head) {
  let current = head;
  let previous = null;
  let next = null;

  while (current !== null) {
    next = current.next;
    current.next = previous;
    previous = current;
    current = next;
  }

  head = previous;
  return head;
}