# 删除排序链表中的重复元素 II
存在一个按升序排列的链表，给你这个链表的头节点 head ，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 没有重复出现 的数字。
返回同样按升序排列的结果链表。
示例 1：
输入：head = [1,2,3,3,4,4,5]
输出：[1,2,5]
示例 2：
输入：head = [1,1,1,2,3]
输出：[2,3]
提示：
- 链表中节点数目在范围
[0, 300] 内 -100 <= Node.val <= 100- 题目数据保证链表已经按升序排列
## 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
```