因为可能删除头结点，所以我们采用dummy哑结点（跟上一篇类似） 

dummy初始化

dummy=ListNode(0,head)

# Definition for singly-linked list.
# class ListNode:
#     def __init__(self, val=0, next=None):
#         self.val = val
#         self.next = next
class Solution:def deleteDuplicates(self, head: Optional[ListNode]) -> Optional[ListNode]:dummy=ListNode(0,head)cur=dummy#起码得有next和next.nextwhile cur.next and cur.next.next:val=cur.next.valif cur.next.next.val==val:#这个时候已经有重复的了，我们使用一个while循环不断删除这个值while cur.next and cur.next.val==val:cur.next=cur.next.next#否则，移动cur即可else: cur=cur.nextreturn dummy.next

 

灵神牛啊