LeetCode: Rotate List

Rotate List

Given a list, rotate the list to the right by k places, where k is non-negative.

For example:
Given 1->2->3->4->5->NULL and k = 2,
return 4->5->1->2->3->NULL.

public class Solution {
    public ListNode rotateRight(ListNode head, int n) {
        // Start typing your Java solution below
        // DO NOT write main() function
        if(head==null) return null;
        ListNode n1 = head,n2=head;
        while(n>0){
            n2=n2.next;
            n--;
            if(n2==null){
                n2=head;
            }
        }
        
        if(n1==n2) return n1;
        
        while(n2.next!=null){
            n1=n1.next;
            n2=n2.next;
        }
        
        ListNode temp = n1.next;
        n2.next=head;
        n1.next=null;
        return temp;
    }
}