Reverse a Linked List problem LeetCode

 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:

Solution :

/**

 * 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 previous=null;

ListNode current=head;

ListNode next = null;

while(current !=null)

{

    next=current.next;

    current.next=previous;

    previous=current;

    current=next;

}

return previous;

    }

}