题目描述
在一个排序的链表中，存在重复的结点，请删除该链表中重复的结点，重复的结点不保留，返回链表头指针。 例如，链表1->2->3->3->4->4->5 处理后为 1->2->5
class ListNode:
def __init__(self, x):
self.val = x
self.next = None
class Solution:
def deleteDuplication(self, pHead):
# write code here
head = ListNode(0)
head.next = pHead
pre = head
p = head.next
while p and p.next:
if p.next.val == p.val:
while p.next and p.next.val == p.val:
p.next = p.next.next
pre.next = p.next
p = pre.next
else:
pre = p
p = p.next
return head.next