Reverse Linked List

Given the head of a singly linked list, reverse the list, and return the reversed list.

Examples

Example 1:

Input: head = [1,2,3,4,5]

Output: [5,4,3,2,1]

Explanation: The list 1→2→3→4→5 becomes 5→4→3→2→1.

Example 2:

Input: head = [1,2]

Output: [2,1]

Explanation: The list 1→2 becomes 2→1.

Example 3:

Input: head = []

Output: []

Explanation: An empty list remains empty after reversal.

Constraints

• The number of nodes in the list is in the range [0, 5000]
• -5000 <= Node.val <= 5000