Reverse Linked List - LeetCode 206

 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: []

 

Solutions:

class Solution {

    public ListNode reverseList(ListNode head) {        

       ListNode previous=null;        

        while(head!=null)

        {

            ListNode nextNode=head.next;            

            head.next=previous;

            previous=head;

            head=nextNode;   

        }        

        return previous;       

    }

}