【LeetCode】82. Remove Duplicates from Sorted List II

1.题目描述

Given a sorted linked list, delete all nodes that have duplicate numbers, leaving only distinct numbers from the original list.

给定一个排序链表，删除所有含有重复数字的节点，只保留原始链表中 没有重复出现 的数字。

Example 1:

Input: 1->2->3->3->4->4->5
Output: 1->2->5

Example 2:

Input: 1->1->1->2->3
Output: 2->3

2.Solutions

public static ListNode deleteDuplicates(ListNode head) {
    if(head == null || head.next == null) return head;
    ListNode dummy=new ListNode(0);
    dummy.next=head;
	//双指针
    ListNode pre=dummy;
    ListNode cur=head;
    while(cur!=null){
        while(cur.next!=null&&cur.val==cur.next.val){
            cur=cur.next;
        }
        if(pre.next==cur)
            pre=pre.next;
        else
            pre.next=cur.next;

        cur=cur.next;
    }
    return dummy.next;
}

（完）