Reverse Linked List

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

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

Solution:

Language: Java

/**
 * 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 ;
        ListNode current = head ;

        while(current!=null)
        {
            ListNode next = current.next ;
            current.next=prev;
            prev=current ;
            current=next ;
        }              
        return prev ;
    }
}