Simplified URL Shortener

Algorithm Design Data Structure

Design and implement a simplified URL shortener service. Your task is to create a program that performs the following operations:

  1. Given a long URL, generate a unique shortened URL. The shortened URL can be a string of fixed or variable length, but it must be unique for each input URL.

  2. If the same long URL is provided again, the service should return the same shortened URL as before (i.e., handle duplicates effectively).

  3. Given a shortened URL, retrieve the original long URL.

Consider the following points:

  • Use appropriate data structures to store the mappings between long URLs and short URLs.

  • Avoid collisions while generating shortened URLs.

  • You do not need to worry about persistence, thread safety, or scaling across multiple machines.

Write code in the programming language of your choice and ensure that your solution can handle a sequence of operations for URL shortening and retrieval in a reasonable time frame.

Include examples of usage and demonstrate that your service works as expected.