题解 | #判断链表中是否有环#
判断链表中是否有环
https://www.nowcoder.com/practice/650474f313294468a4ded3ce0f7898b9
#include <stdbool.h> /** * struct ListNode { * int val; * struct ListNode *next; * }; */ /** * * @param head ListNode类 * @return bool布尔型 */ bool hasCycle(struct ListNode* head ) { if(head == NULL) return false; struct ListNode *slow = head; struct ListNode *fast = head->next;//经典快慢指针 while (slow != NULL && fast != NULL && fast->next != NULL) //快慢指针需要考虑快指针的越界问题 { if(slow == fast) { return true; } else { slow = slow->next; fast = fast->next->next; continue; } } return false; }