leetcode

0 class Solution {

1 public:

2 bool hasCycle(ListNode *head) {

3 if (!head) return false;

4

5 ListNode *slow, *fast;

6 fast = slow = head;

7 while (fast->next && fast->next->next) {

8 fast = fast->next->next;

9 slow = slow->next;

10 if (fast == slow) return true;

11 }

12 return false;

13 }

14 };