题解 | #判断链表中是否有环#

/**
 * Definition for singly-linked list.
 * struct ListNode {
 *     int val;
 *     ListNode *next;
 *     ListNode(int x) : val(x), next(NULL) {}
 * };
 */
#include <cmath>
#include <cstddef>
#include <limits>
class Solution {
  public:
    bool hasCycle(ListNode* head) {
        int j=0;
        ListNode* fast = head;
        ListNode* slow = head;
        if(head==NULL||head->next==NULL)
        {
            return false;
        }
        for (int i = 0; i <= 9999; i++) {
            head=head->next;
            j++;
            if (head->next == NULL) 
            {
                break;
            }    

        }
        if(j==10000)
        {
            return true;
        }
        else 
        {
            return false;
        }
    }
};