Given a linked list, determine if it has a cycle in it.
Follow up: Can you solve it without using extra space?
C++
/** * 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 (NULL == head) return false; while(fast && fast->next){ fast = fast->next->next; slow = slow->next; if(NULL != fast && slow == fast) return true; } return false; } };
转载于:https://www.cnblogs.com/vercont/p/10210278.html
