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]

Example 2:

Input: head = [1,2]
Output: [2,1]

Example 3:

Input: head = []
Output: []

Constraints

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

Note

For this problem, the LinkedList node is defined as:

JavaScript:

class ListNode {
    constructor(val, next) {
        this.val = (val===undefined ? 0 : val)
        this.next = (next===undefined ? null : next)
    }
}

Python:

class ListNode:
    def __init__(self, val=0, next=None):
        self.val = val
        self.next = next