Linked List Cycle
Given a linked list, determine if it has a cycle in it.
Follow up:
Can you solve it without using extra space?
更简单的环题
/** * 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; ListNode *slow = head; if(head == NULL || head->next == NULL || head->next->next==NULL)return 0; while(1) { slow = slow->next; fast = fast->next; if(fast==NULL)return 0; fast = fast->next; if(fast==NULL)return 0; if(fast == slow)return 1; } } };
posted on 2014-03-26 16:35 pengyu2003 阅读(118) 评论(0) 编辑 收藏 举报