206. Reverse Linked List

Level: Easy
Related topics: Recursion
Link: https://leetcode.com/problems/reverse-linked-list/

Problem

Reverse a singly linked list.

Example

Input: 1->2->3->4->5->NULL
Output: 5->4->3->2->1->NULL

Follow up:

A linked list can be reversed either iteratively or recursively. Could you implement both?

Solution

• Approach 1: Iterative
• Approach 2: Recursive