LeetCode-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.

/**
 * Definition for singly-linked list.
 * public class ListNode {
 *     int val;
 *     ListNode next;
 *     ListNode(int x) { val = x; }
 * }
 */

public class Solution {
    public ListNode rotateRight(ListNode head, int k) {
        if(head==null || head.next==null || k==0){
            return head;
        }
        ListNode p=head;
        int len=1;
        while(p.next!=null){
            len++;
            p=p.next;
        }
        p.next=head;
        int l=k%len;
        for(int i=0; i<len-l; i++){
            p=p.next;
        }
        head=p.next;
        p.next=null;
        
        return head;
    }
}