Given a linked list, determine if it has a cycle in it.
Follow up:
Can you solve it without using extra space?
这个是用快慢指针,记得边界条件的判断就行了。
/**
* Definition for singly-linked list.
* class ListNode {
* int val;
* ListNode next;
* ListNode(int x) {
* val = x;
* next = null;
* }
* }
*/
// 16:48->16:51 pass
public class Solution {
public boolean hasCycle(ListNode head) {
ListNode n1,n2;
n1 = n2 = head;
if(head==null)
{
return false;
}
while(true)
{
if(n2==null || n2.next==null)
{
break;
}else
{
n2 = n2.next.next;
}
n1 = n1.next;
if(n1==n2)
{
return true;
}
}
return false;
}
}
Linked List Cycle,布布扣,bubuko.com
原文地址:http://blog.csdn.net/nan327347465/article/details/38339179