> For the complete documentation index, see [llms.txt](https://junnie.gitbook.io/nine-chapter/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://junnie.gitbook.io/nine-chapter/5.linkedlist/113remove-duplicates-from-sorted-list-ii.md).

# 82.Remove Duplicates from Sorted List II (M)

## 1.Description(Medium)

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

**Example**

Given`1->2->3->3->4->4->5`, return`1->2->5`.\
Given`1->1->1->2->3`, return`2->3`.

## 2.Code

<https://www.jiuzhang.com/solutions/remove-duplicates-from-sorted-list-ii/>

此题与112相比，有可能会换head,所以要用dummy来做。而且要一次性删完所有的重复值。

```
 public static ListNode deleteDuplicates(ListNode head) {
        if(head==null){
            return null;
        }

        ListNode dummy=new ListNode(0);
        dummy.next=head;
        ListNode prev=dummy;

        while(prev.next!=null && prev.next.next!=null){

            if(prev.next.val==prev.next.next.val){
                //要一次性删完
                int value=prev.next.val;
                while(prev.next!=null && prev.next.val==value){
                    prev.next=prev.next.next;
                }
            }
            else{
                prev=prev.next;
            }          
        }

        return dummy.next;
    }
```