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) {
        // write code here
        ListNode tmp=head;
        if(head==null||head.next==null) return head;
        while(head!=null&&head.next!=null&&head.val==head.next.val)
        {
            int i = 0;
            while(head!=null&&head.next!=null&&head.val==head.next.val) {head = head.next;tmp=head.next;i=1;}
            if(i==1) head = tmp;
        }

        if(tmp==null) return tmp;

        tmp.next = deleteDuplicates(tmp.next);
        return tmp;
    }
}