题解 | #判断链表中是否有环#

public class Solution {
    public boolean hasCycle(ListNode head) {
        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;
    }
}