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 ) {
// write code here
if((head==NULL)||(head->next==NULL)){
return false;
}
struct ListNode *fast=head;
struct ListNode *slow=head;
while(1){
fast=fast->next;
fast=fast->next;
slow=slow->next;
if(fast==slow){
return true;
}
if((fast==NULL)||(fast->next==NULL)){
return false;
}
}
}
快慢指针判断
）。