题解 | #删除有序链表中重复的元素-I#

# 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
        dummy_head = ListNode(-100000000)
        dummy_head.next = head
        pre, cur = dummy_head, head
        while cur:
            if pre.val == cur.val:
                pre.next = cur.next
            else:
                pre = pre.next
            cur = cur.next

        return dummy_head.next

这里需要注意的是如果pre和cur值相同修改pre.next后，就不要在走pre=pre.next这条逻辑了。