Given a linked list, determine if it has a cycle in it.
Follow up:
Can you solve it without using extra space?
1 /** 2 * Definition for singly-linked list. 3 * struct ListNode { 4 * int val; 5 * ListNode *next; 6 * ListNode(int x) : val(x), next(NULL) {} 7 * }; 8 */ 9 class Solution { 10 public: 11 bool hasCycle(ListNode *head) { 12 ListNode *slow=head; 13 ListNode *fast=head; 14 15 while(fast&&fast->next) 16 { 17 slow=slow->next; 18 fast=fast->next->next; 19 if(slow==fast) return true; 20 } 21 return false; 22 23 } 24 };
时间: 2024-10-03 22:29:20