【LeetCode】535. Encode and Decode TinyURL

这几天陆续听说同学们都在刷LeetCode，是面试必须的。听完我也坐不住了，决定开始刷起来。先在知乎看了一遍，大部分人都是按照AC rate从高到低刷，那么我也就这么办吧。同学还建议直接在网页上写代码，这样可以适应在线笔试时的手写要求。

稍后把解决方案放到GitHub上去。

问题描述

问题连接：https://leetcode.com/problems/encode-and-decode-tinyurl/#/description

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.

我的代码

public class Codec {

private static Map<String,String> dict = new HashMap<String,String>();

// Encodes a URL to a shortened URL.
public String encode(String longUrl) {
String tinyUrl = "http://tinyurl.com/" + longUrl.hashCode();
dict.put(tinyUrl,longUrl);
return tinyUrl;
}

// Decodes a shortened URL to its original URL.
public String decode(String shortUrl) {
return dict.get(shortUrl);
}
}

// Your Codec object will be instantiated and called as such:
// Codec codec = new Codec();
// codec.decode(codec.encode(url));

基本思路就是偷懒，用Java自带的HashCode，然后把结果存起来。人家正规的估计不是那么做的，我们来看一下。

讨论区

哈哈，好高兴啊，同学们也是这么搞的，比如那个最高view的https://discuss.leetcode.com/topic/81637/two-solutions-and-thoughts/2

另外还有直接返回的和用Base64的，感觉都挺逗的~