LeetCode 535. Encryption and decryption of tinyurl

535. TinyURL Encryption and decryption

 

【 analysis 】 In fact, this question is mainly about setting two strings , How to map between two strings , Then the simplest one is to use the same string directly . Or you can use self increasing ID For hash mapping .

public class Codec {

    Map<Integer, String> map = new HashMap();
    int cnt = 0;

    // Encodes a URL to a shortened URL.
    public String encode(String longUrl) {
        map.put(cnt++, longUrl);
        return Integer.toString(cnt - 1);
    }

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