LL 6 - Reverse Linked List
Problem
Given the head of a singly linked list, reverse the list, and return the reversed list. (link)
Example 1:
Input: head = [1,2,3,4,5]
Output: [5,4,3,2,1]
Example 2:
Input: head = [1,2]
Output: [2,1]
Example 3:
Input: head = []
Output:
Solu...
