题目
. - 力扣(LeetCode) 环形链表判定
代码
/*** Definition for singly-linked list.* class ListNode {* int val;* ListNode next;* ListNode(int x) {* val = x;* next = null;* }* }*/
public class Solution {public boolean hasCycle(ListNode head) {ListNode node = head;ListNode preNode = head;while (node.next != null) {boolean cycle = false;while (preNode != node) {
// System.out.println("val = " + preNode.val);if (node.next == preNode) {return true;}preNode = preNode.next;}
// System.out.println("cycle = " + cycle);//if (cycle) {// return true;//}node = node.next;preNode = head;}return false;}
}