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.

Runtime: 12ms.

/**
 * 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 || !head->next) return head;
        
        // first find the (n - k % n)th element
        ListNode* move = head;
        int count = 1;
        while(move->next) {
            count++;
            move = move->next;
        }
        ListNode* endNode = move;
        
        k %= count;
        move = head;
        int index = 0;
        while(index++ < k)
            move = move->next;
    
        ListNode* current = head;
        while(move->next) {
            move = move->next;
            current = current->next;
        }
        endNode->next = head;
        head = current->next;
        current->next = NULL;
       
        return head;
    }
};