Reverse Linked List

Given the head of a Singly LinkedList, reverse the list, and return the head of the reversed list.

Example 1:

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

/**
 * Definition for singly-linked list.
 * public class ListNode {
 *     int val;
 *     ListNode next;
 *     ListNode() {}
 *     ListNode(int val) { this.val = val; }
 *     ListNode(int val, ListNode next) { this.val = val; this.next = next; }
 * }
 */
class Solution {
    public ListNode reverseList(ListNode head) {
        ListNode prev = null;
        var temp = head;
        while (temp != null) {
            var front = temp.next;
            temp.next = prev;
            prev = temp;
            temp = front;
        }
        return prev;
    }
}