Challenge: Reverse Linked List

Statement

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

Constraints:

Let n be the number of nodes in a linked list.

• $1 \leq$ n $\leq 5\times10^2$
• $-5\times10^3 \leq$ Node.value $\leq 5\times10^3$

Examples