61. 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.

/** * Definition for singly-linked list. * struct ListNode { *     int val; *     ListNode *next; *     ListNode(int x) : val(x), next(NULL) {} * }; */class Solution {public:    int getLen(ListNode* head)    {        int len = 0;        while(head)        {            len++;            head = head->next;        }        return len;    }      ListNode* rotateRight(ListNode* head, int k) {        if(head==NULL) return NULL;        ListNode* fast = head;        int i;        int len = getLen(head);        k = k % len;        if(k==0) return head;        int n = len - k;        for(i=1; i<n; i++)        {            fast = fast->next;        }       ListNode *head2 = fast->next;       fast->next = NULL;         ListNode* slow = head2;       for(int j = 1; j <k; j++)       {           slow = slow->next;       }       slow->next = head;       return head2;           }};