URL Shortener with Compression

URL Shortener Service

Design a URL shortening service similar to TinyURL. The service should support two operations:

encode(longUrl):

• Convert a long URL into a shortened URL
• The same long URL should always return the same short URL
• Each unique URL should get a unique short code

decode(shortUrl):

• Convert a shortened URL back to the original long URL
• Return empty string if the short URL doesn't exist

Requirements:

1. Short URLs should be deterministic (same input = same output)
2. Must handle duplicate encode requests (return existing short URL)
3. Must handle non-existent decode requests gracefully

Example:

encode("https://leetcode.com") → "http://tiny/0" encode("https://example.com") → "http://tiny/1" decode("http://tiny/0") → "https://leetcode.com"