leetcode-535-Encode-and-Decode-TinyURL

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描述

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

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.

分析

实现一个短链接服务，需要实现编码，解码方法，实际上就是写一个哈希算法，貌似没多少测试数据进行判断，居然还是一道 Medium 难度的题。

解决方案1(Java)

直接使用字符串的 hashCode 函数实现。

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public class Codec {
    Map<Integer, String> map = new HashMap<>();

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

    // Decodes a shortened URL to its original URL.
    public String decode(String shortUrl) {
        return map.get(Integer.parseInt(shortUrl.replace("http://tinyurl.com/", "")));
    }
}

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

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