题解 | #判断链表中是否有环#

/**

• Definition for singly-linked list.

• struct ListNode {

• int val;
  

• ListNode *;
  

• ListNode(int x) : val(x), next(NULL) {}
  

• }; */ class Solution { public: bool hasCycle(ListNode *head) {

   if(head == nullptr || head->next == nullptr)  return 0;
   
   ListNode *slow = head;
   ListNode *fast = head;
   
   while(fast->next && fast->next->next)
   {
       fast= fast->next->next;
        slow= slow->next;
      if(slow == fast)
       {
           return 1;
       }
      
       
   }
  
   return 0;
   
  

  } };