Multiplayer Matchmaking Arena

A browser-accessible matchmaking system powered by a C++ DSA engine.

🌐 Live Demo

Open in browser: https://your-app.onrender.com

Multiple users can join simultaneously and get matched in real-time!

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🏗️ Architecture

Browser  ─────WebSocket────▶  Node.js Bridge  ────stdin/stdout────▶  C++ Engine
(HTML/JS)                     (server.js)                           (matchmaking_engine.cpp)
    │                              │                                       │
    │  Send: JOIN, QUEUE           │  Spawn & manage                       │  AVL Tree
    │  Recv: MATCHED, QUEUED       │  Route messages                       │  Hash Table
    │                              │                                       │  Queue
    ▼                              ▼                                       ▼

Key Points:

• All matchmaking logic runs in C++ (preserved DSA)
• Node.js only routes messages (no game logic)
• Browser connects via WebSocket
• Single container deployment on Render.com

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🚀 Quick Start (Local)

1. Build C++ Engine

cd backend-cpp
g++ -std=c++11 -O2 -o engine matchmaking_engine.cpp

2. Install Node.js Dependencies

cd bridge
npm install

3. Start Server

node server.js

4. Open Browser

Go to: http://localhost:3000

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☁️ Deploy to Render.com

Option 1: Blueprint (Recommended)

1. Push code to GitHub
2. Go to render.com → New → Blueprint
3. Connect your repository
4. Render auto-detects render.yaml and deploys

Option 2: Manual

1. Go to Render → New → Web Service
2. Connect GitHub repo
3. Settings:
   • Runtime: Docker
   • Dockerfile Path: ./Dockerfile
4. Deploy

Your public URL will be: https://matchmaking-arena.onrender.com

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📁 Project Structure

/backend-cpp/
  matchmaking_engine.cpp    # C++ stdin/stdout server
  /ds/                      # Data structures (AVL, Hash, Queue, List)
  /models/                  # Player, Match models
  /services/                # Matchmaker, Ranking, History

/bridge/
  server.js                 # Node.js WebSocket bridge
  package.json              # Node dependencies
  /public/
    index.html              # Browser UI

Dockerfile                  # Container build
render.yaml                 # Render.com config

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📡 Protocol

Browser → Server (WebSocket JSON)

{"cmd":"JOIN","username":"Ahmed","elo":1200}
{"cmd":"QUEUE","playerId":1,"game":"pingpong"}
{"cmd":"LEAVE","playerId":1}
{"cmd":"STATUS","playerId":1}

Server → Browser (WebSocket JSON)

{"type":"CONNECTED","clientId":"ws-1-1234567890"}
{"type":"OK","playerId":1}
{"type":"QUEUED","position":2}
{"type":"MATCHED","matchId":5,"opponent":"BOT_3","opponentElo":1150}

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📊 DSA Features

Data Structure	Purpose	Complexity
AVL Tree	ELO-based closest opponent matching	O(log n)
Hash Table	Player storage by ID	O(1) average
Queue	FIFO matchmaking lobby per game	O(1)
LinkedList	Match history, hash collision chains	O(1) append

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🎮 Games

• 🏓 Ping Pong
• 🐍 Snake Battle
• 🎯 Tank Wars

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📝 License

Academic project for educational purposes.