LeetCode-Linked List Cycle
Given a linked list, determine if it has a cycle in it. Follow up: Can you solve it without using extra space?
runner 问题,注意while循环条件;
/** * 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) { if(head == null || head.next == null || head.next.next == null){ return false; } ListNode fast = head; ListNode slow = head; while(fast !=null && fast.next != null){ fast = fast.next.next; slow = slow.next; if(fast == slow){ return true; } } return false; } }
posted on 2015-03-18 06:15 IncredibleThings 阅读(133) 评论(0) 编辑 收藏 举报