Leetcode刷题记录：编码并解码短网址

# 使用随机函数，生成短网址，保存在dict中，避免重复
import random
import math
import re

class Codec:
    charbase = [x for x in "0123456789abcdefghijklmnopqrstuvwxyz"] 
    urldict = {}
    longurldict = {}

    def get_random_char(self, length):
        random_char = ""
        #print(len(self.charbase))

        for x in range(6):
            random_char += self.charbase[math.ceil(random.random() * len(self.charbase) ) - 1 ]

        return random_char

    def encode(self, longUrl):
        if longUrl in self.longurldict:
            return self.longurldict[longUrl]

        url_code = self.get_random_char(6)
        if url_code in self.urldict:
            self.encode(longUrl)
        else:
            self.longurldict[longUrl] = url_code
            self.urldict[url_code] = longUrl

        return "http://tinyurl.com/" + url_code

    def decode(self, shortUrl):
        domain = "http://tinyurl.com/"
        shortUrl = shortUrl.replace(domain, "")

        if shortUrl in self.urldict:
            return self.urldict[shortUrl]
        else:
            return false

url = "https://leetcode.com/problems/design-tinyurl";
codec = Codec()
print(codec.get_random_char(6))
print(codec.get_random_char(6))
print(codec.get_random_char(6))
print(codec.get_random_char(6))
print(codec.get_random_char(6))

print(codec.encode(url))
print(codec.decode(codec.encode(url)))