Design URL Shortener Core Logic

Node.js

Technical Specification

Implement the in-memory logic for a URL shortener: createShortUrl(longUrl) and getLongUrl(shortCode).

Input/Output Samples

Input:createShortUrl('https://example.com')

Output:abc123

Input:getLongUrl('abc123')

Output:https://example.com

Optimal Logic Path

const store = new Map();

function createShortUrl(longUrl) {
  const code = Math.random().toString(36).slice(2, 8);
  store.set(code, longUrl);
  return code;
}

function getLongUrl(code) {
  return store.get(code) || null;
}

module.exports = { createShortUrl, getLongUrl };

Architectural Deep-Dive

We map random short codes to original URLs; in real apps we'd also validate and persist.