删除链表中重复的结点

# -*- coding:utf-8 -*-
# class ListNode:
#     def __init__(self, x):
#         self.val = x
#         self.next = None
class Solution:
    def deleteDuplication(self, pHead):
        # write code here
        if pHead==None or pHead.next==None:
            return pHead
        p=pHead.next
        if p.val!=pHead.val:
            pHead.next=self.deleteDuplication(p)
        else:
            while p.val==pHead.val and p.next!=None:
                p=p.next
            if p.val!=pHead.val:
                pHead=self.deleteDuplication(p)
            else:
                return None
        return pHead