题解 | #删除有序链表中重复的元素-II#

# 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 None
        res = ListNode(-1)
        res.next = head
        cur = res
        while cur.next and cur.next.next:
            if cur.next.val == cur.next.next.val:
                temp = cur.next.val
                while cur.next and cur.next.val == temp:
                    cur.next = cur.next.next
            else:
                cur = cur.next
        return res.next