/**

 * Definition for singly-linked list.

 * struct ListNode {

 *     int val;

 *     ListNode *next;

 *     ListNode(int x) : val(x), next(NULL) {}

 * };

 */

class Solution {

public:

    ListNode* rotateRight(ListNode* head, int k) {

        if(head == NULL || k<= || head->next == NULL)

        {

            return head;

        }

        ListNode *p1 = head, *p2 = head, *p = NULL;

        int size=;

        while(p1->next !=NULL)   //求链表长度

        {

            p1 = p1->next;

            size++;

        }

        if(k%size == )          //是整倍数直接返回

        {

            return head;

        }

        k = k%size;

        p1 = head;

        while(p1 ->next != NULL)    //移动p1,p2；

        {

            p1 = p1->next;

            if(k <=)

            {

                p2 = p2->next;

            }

            else

            {

                k--;

            }

        }

        p = p2->next;

        p2->next = NULL;

        p1->next = head;

        return p;

    }

};