题目链接:https://leetcode-cn.com/problems/linked-list-cycle/ 给定一个链表,判断链表中是否有环。
解题思路:快慢指针,参考我的博客
/**
* Definition for singly-linked list.
* struct ListNode {
* int val;
* ListNode *next;
* ListNode(int x) : val(x), next(NULL) {}
* };
*/
class Solution {
public:
bool hasCycle(ListNode *head)
{
ListNode *fast = head, *slow = head;
while(fast && fast->next)
{
fast = fast->next->next;
slow = slow->next;
if(fast && fast == slow)
return true;
}
return false;
}
};