R8-链表篇
思路:
使用快慢指针,快指针走两步,慢指针走一步。追上,有环。
/*** 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 slow=head,fast=head;while (fast!=null&& fast.next!=null){slow=slow.next;fast=fast.next.next;if (fast==slow)return true;}return false;}
}
还没啥人做java,估计是没落了??