Given a list, rotate the list to the right bykplaces, wherekis non-negative.

Example:

Given 
1-
>
2-
>
3-
>
4-
>
5-
>
NULL
 and 
k
 = 
2
,

return 
4-
>
5-
>
1-
>
2-
>
3-
>
NULL
.

tag: LinkedList

/**
 * Definition for singly-linked list.
 * public class ListNode {
 *     int val;
 *     ListNode next;
 *     ListNode(int x) { val = x; }
 * }
 */
class Solution {
    public ListNode rotateRight(ListNode head, int k) {
        if (head == null) return null;

        ListNode fast = head;
        int len = 1;
        while (fast.next != null){
            fast = fast.next;
            len++;
        }
        fast.next = head;

        k = k % len;

        int lenlen = len - k;
        ListNode slow = fast;
        while (lenlen > 0){
            slow = slow.next;
            lenlen--;
        }

        ListNode ans = slow.next;
        slow.next = null;

        return ans;
    }
}