题解 | 判断链表中是否有环

少儿编程罢了

/**
 * 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) {

        short num = 1;
        while(head != nullptr) {
            head = head->next;
            // 计算链表长度
            num++;
            if (num > 10000) {
                break;
            }
        }

        if (num > 10000) {
            return true;
        } else {
            return false;
        }
    }
};