Problem Statement:

Given the head of a singly linked list, your task is to reverse the list and return its head. The singly linked list has nodes, and each node contains an integer and a pointer to the next node. The last node in the list points to null, indicating the end of the list.

Examples

Example 1:

• Input: [3, 5, 2]
• Expected Output: [2, 5, 3]
• Justification: Reversing the list [3, 5, 2] gives us [2, 5, 3].

Example 2:

• Input: [7]
• Expected Output: [7]