题解 | #删除有序链表中重复的元素-I#

import java.util.*;

/*
 * public class ListNode {
 *   int val;
 *   ListNode next = null;
 * }
 */

public class Solution {
    /**
     *
     * @param head ListNode类
     * @return ListNode类
     */
    public ListNode deleteDuplicates (ListNode head) {
        ArrayList<Integer> list = new ArrayList<>();
        ListNode p = head;
        ListNode q = head;
        ListNode res = new ListNode(0);
        res.next = head;
        while (p != null) {
            if (list.contains(p.val)) {
                    ListNode next = p.next;
                    p.next = null;
                    q.next = next;
                    p=next;
                }
            else{
                q = p;
                p = p.next;
                list.add(q.val);
            }
        }
            return res.next;
    }
}