题目:
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:
ListNode *rotateRight(ListNode *head, int k) {
if (head == NULL)
return head;
ListNode *cur = head;
//s为节点个数
int s = 1;
while (cur->next != NULL) {
s++;
cur = cur->next;
}
ListNode *tail = cur;
k = (s-k%s)%s;
if (k == 0)
return head;
cur = head;
int a = 1;
while (a < k) {
cur = cur->next;
a++;
}
ListNode *head2 = cur->next;
cur->next = NULL;
tail->next = head;
return head2;
}
};