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) {

        ListNode dummy = new ListNode(Integer.MIN_VALUE);
        dummy.next = head;
        ListNode pre = dummy;
        ListNode cur = head;

        while (cur != null) {
            if (cur.val == pre.val) {
                cur = cur.next;
                pre.next = null;
            } else {
                ListNode next = cur.next;
                pre.next = cur;
                pre = cur;
                cur = next;
            }
        }

        return dummy.next;
    }
}