Rotate List

 1 public class Solution {
 2     public ListNode rotateRight(ListNode head, int n) {
 3         if(head==null || n==0) return head;
 4         int len = 1;
 5         ListNode p = head;
 6         while(p.next!=null){
 7             p = p.next;
 8             len++;
 9         }
10         p.next = head;
11         for(int i=0;i<len -n%len;i++){
12             p = p.next;
13         }
14         head = p.next;
15         p.next= null;
16         return head;
17     }
18 }