题解 | #判断链表中是否有环#

#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
    struct ListNode* head1,*head2;
    head1=head2=head;
    while(head2&&head2->next){
       
        head2=head2->next->next;
       

        head1=head1->next;
        if(head1==head2)return true;
    }
    return false;
}