题解 | #删除有序链表中重复的元素-II#

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) {
        if(head == null)
            return null;
   
        ListNode dummy = new ListNode(1001);
        dummy.next = head;
        ListNode cur = head;
        ListNode pre = dummy;
        while(cur!=null&&cur.next!=null){
            if(cur.val==cur.next.val){
                int tmp = cur.val;
                while(cur!=null && cur.val==tmp){
                    cur = cur.next;
                }
                pre.next = cur;

            }else{
                pre = pre.next;
                cur = cur.next;
            }

        }




        return dummy.next;

        // write code here
    }
}