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) {
        // write code here
        if (head == null || head.next == null) {
            return head;
        }
        ListNode newHead = new ListNode(-1);
        ListNode node = newHead;
        node.next = head;
        head = head.next;
        node = node.next;
        node.next = null;
        while (head != null) {
            if (head.val == node.val) {
                head = head.next;
            } else {
                node.next = head;
                head = head.next;
                node = node.next;
                node.next = null;
                
            }
        }
        return newHead.next;
    }
}