/**  * Definition for singly-linked list.  * struct ListNode {  *   int val;  *   ListNode *next;  *   ListNode(int x) : val(x), next(NULL) {}  * };  */ class Solution { public:   /**    * @param head: the list    * @param k: rotate to the right k places    * @return: the list after rotation    */   ListNode *rotateRight(ListNode *head, int k) {     // write your code here     if(head==NULL)       return head;     int len = 0;     ListNode*temp = head;     while(temp)     {       len++;       temp = temp->next;     }     k%=len;     if(k==0)       return head;     k = len-k;     temp = head;     while(k>1)     {       temp = temp->next;       k--;     }     ListNode*newStart = temp->next;     temp->next = NULL;     temp = newStart;     while(temp->next)       temp = temp->next;     temp->next = head;     return newStart;   } };