题解 | #链表中环的入口结点#

import java.util.*;
/*
 public class ListNode {
    int val;
    ListNode next = null;

    ListNode(int val) {
        this.val = val;
    }
}
*/
public class Solution {

    public ListNode EntryNodeOfLoop(ListNode pHead) {
        ArrayList arrylist = new ArrayList();
        while (pHead != null) {
            if (arrylist.size() != 0) {
                if (arrylist.contains(pHead.val)) {
                    return pHead;
                }
            }
            arrylist.add(pHead.val);
            pHead = pHead.next;
        }
        return null;
    }
}