题解 | #判断链表中是否有环#快慢指针
判断链表中是否有环
http://www.nowcoder.com/practice/650474f313294468a4ded3ce0f7898b9
/**
* 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){
fast = fast.next.next;
slow = slow.next;
if( slow == fast) return true;
}
return false;
}
}
* 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){
fast = fast.next.next;
slow = slow.next;
if( slow == fast) return true;
}
return false;
}
}