20170613-leetcode-535-Encode and Decode TinyURL

1.Description

Note: This is a companion problem to the System Design problem: Design TinyURL.

TinyURL is a URL shortening service where you enter a URL such as https://leetcode.com/problems/design-tinyurl and it returns a short URL such as http://tinyurl.com/4e9iAk.

Design the encode and decode methods for the TinyURL service. There is no restriction on how your encode/decode algorithm should work. You just need to ensure that a URL can be encoded to a tiny URL and the tiny URL can be decoded to the original URL.
解读
设计一种ecode和decode的算法，

2.Solution

思路：
encode，按照顺序把原来的url存入到list中，并把添加的顺序转化成数字替换结尾的字符；
decode，首先找到编码之后结尾的数字，然后根据索引找到真实的url的值

class Codec:    def __init__(self):        self.urls = []    def encode(self, longUrl):        self.urls.append(longUrl)        return 'http://tinyurl.com/' + str(len(self.urls) - 1)    def decode(self, shortUrl):        return self.urls[int(shortUrl.split('/')[-1])]