535. Encode and Decode TinyURL

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.

public class Codec {
List<String> url = new ArrayList<>();
// Encodes a URL to a shortened URL.
public String encode(String longUrl) {
url.add(longUrl);
return "http://tinyurl.com/" + (url.size()-1);
}

// Decodes a shortened URL to its original URL.
public String decode(String shortUrl) {
String[] ss = shortUrl.split("/");
int n = Integer.parseInt(ss[ss.length-1]);
return url.get(n);
}
}

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