# 删除排序链表中的重复元素 II

<p>存在一个按升序排列的链表，给你这个链表的头节点 <code>head</code> ，请你删除链表中所有存在数字重复情况的节点，只保留原始链表中 <strong>没有重复出现</strong><em> </em>的数字。</p><p>返回同样按升序排列的结果链表。</p><p> </p><p><strong>示例 1：</strong></p><img alt="" src="https://img-service.csdnimg.cn/img_convert/5b9243e41528c71944e0f9436d8c249f.jpeg" style="width: 500px; height: 142px;" /><pre><strong>输入：</strong>head = [1,2,3,3,4,4,5]<strong><br />输出：</strong>[1,2,5]</pre><p><strong>示例 2：</strong></p><img alt="" src="https://img-service.csdnimg.cn/img_convert/f43c3f1fdb51738ae73ac8543c9b4e9b.jpeg" style="width: 500px; height: 205px;" /><pre><strong>输入：</strong>head = [1,1,1,2,3]<strong><br />输出：</strong>[2,3]</pre><p> </p><p><strong>提示：</strong></p><ul>	<li>链表中节点数目在范围 <code>[0, 300]</code> 内</li>	<li><code>-100 <= Node.val <= 100</code></li>	<li>题目数据保证链表已经按升序排列</li></ul>

## template

```python
class ListNode(object):
	def __init__(self, x):
		self.val = x
		self.next = None
class LinkList:
	def __init__(self):
		self.head=None
	def initList(self, data):
		self.head = ListNode(data[0])
		r=self.head
		p = self.head
		for i in data[1:]:
			node = ListNode(i)
			p.next = node
			p = p.next
		return r
	def	convert_list(self,head):
		ret = []
		if head == None:
			return
		node = head
		while node != None:
			ret.append(node.val)
			node = node.next
		return ret
class Solution(object):
	def deleteDuplicates(self, head):
		"""
		:type head: ListNode
		:rtype: ListNode
		"""
		newnodehead = None
		newnode = None
		node = head
		while node:
			lastval = node.val
			if node.next and node.next.val == lastval:
				while node and node.val == lastval:
					node=node.next
				continue
			if not newnodehead:
				newnode=ListNode(node.val)
				newnodehead=newnode
			else:
				newnode.next=ListNode(node.val)
				newnode=newnode.next
			node = node.next
		return newnodehead
# %%
l = LinkList()
list1 = [1,2,3,3,4,4,5]
l1 = l.initList(list1)
s = Solution()
print(l.convert_list(s.deleteDuplicates(l1)))
```

## 答案

```python

```

## 选项

### A

```python

```

### B

```python

```

### C

```python

```