# class ListNode:
# def __init__(self, x):
# self.val = x
# self.next = None
#
# 代码中的类名、方法名、参数名已经指定,请勿修改,直接返回方法规定的值即可
#
#
# @param head ListNode类
# @return ListNode类
#
class Solution:
def deleteDuplicates(self , head: ListNode) -> ListNode:
# write code here
if not head:
return head
cur=head
while cur.next:
if cur.val ==cur.next.val:
cur.next=cur.next.next
else:
cur=cur.next
return head