Rotate List

/**
 * Definition for singly-linked list.
 * public class ListNode {
 *     int val;
 *     ListNode next;
 *     ListNode(int x) {
 *         val = x;
 *         next = null;
 *     }
 * }
 */
public class Solution {
    public ListNode rotateRight(ListNode head, int n) {
        // IMPORTANT: Please reset any member data you declared, as
        // the same Solution instance will be reused for each test case.
        if(head == null || n == 0)
            return head;
        ListNode pivot = head;
        int len = 1;
        while(pivot.next != null)
        {
            len++;
            pivot = pivot.next;
        }
        pivot.next = head;
        n = n%len; //if n>len, need to go around the loop for several times
        for(int i=0; i<len-n; i++)
        {
            pivot = pivot.next;
        }
        head = pivot.next;
        pivot.next = null;
        return head;
    }
}