剑指offer54-字符流中第一个不重复的字符

# -*- coding:utf-8 -*-
class Solution:
    # 返回对应char
    def __init__(self):
        self.stock={}
        self.queue=[]
    def FirstAppearingOnce(self):
        # write code here
        if len(self.queue)==0:
            return ‘#‘
        return self.queue[0]
    def Insert(self, char):
        # write code here
        if char not in self.stock:
            self.queue.append(char)
            self.stock[char]=1          --这里stock可以是list，也可以是dict，只是为了记录char是否在之前出现过。
        else:
            try:
                self.queue.remove(char)
            except:
                pass

ss=Solution()
ss.Insert("h")
ss.FirstAppearingOnce()
ss.Insert("e")
ss.FirstAppearingOnce()
ss.Insert( "l")
ss.FirstAppearingOnce()
ss.Insert( "l")
ss.FirstAppearingOnce()
ss.Insert( "o")
ss.FirstAppearingOnce()
ss.Insert( "w")
ss.FirstAppearingOnce()
ss.Insert( "o")
ss.FirstAppearingOnce()
ss.Insert( "l")
ss.FirstAppearingOnce()
ss.Insert( "d")
ss.FirstAppearingOnce()