Connect 4 AI Game 🔴🟡

A modern, web-based Connect 4 game featuring an intelligent AI opponent powered by the Minimax algorithm with Alpha-Beta Pruning. Challenge yourself against a strategic AI that thinks 5 moves ahead!

✨ Features

• 🧠 Intelligent AI Opponent — Minimax with Alpha-Beta Pruning for strategic gameplay
• 👥 Multi-User Support — Each browser gets its own game session
• 📱 Responsive Design — Seamless experience on desktop, tablet, and mobile devices
• ⚡ Fast Performance — AI makes decisions in under 1 second
• 🎨 Modern UI — Clean interface with smooth animations and visual feedback
• 🎯 Strategic Depth — AI analyzes up to 5 moves ahead for challenging gameplay

🧠 AI Performance Metrics

Metric	Value
Search Depth	5 levels
Average Response	< 1 second
Nodes Evaluated	10,000 - 50,000 per move
Algorithm	Minimax + Alpha-Beta Prune
Difficulty Level	Challenging

🚀 Quick Start

Prerequisites

• Python 3.7 or higher
• Git

Installation & Setup

1. Clone the repository

   git clone https://github.com/viliusjan/connect4-ai.git
   cd connect4-ai

2. Install the project's requirements

   pip install flask

3. Generate a Flask secret key
   Run this in Python:

   import secrets
   print(secrets.token_hex(32))

   Copy the generated string.

4. Set your secret key in connect4.py

   app = Flask(__name__)
   app.secret_key = 'paste_your_generated_secret_key_here'

5. Run the game locally

   python3 connect4.py

6. Open your browser

   Navigate to: http://localhost:8000
   

📁 Project Structure

connect4-ai/
├── connect4.py          # Main Flask application (session-based, multi-user)
├── templates/           # HTML templates
└── README.md            # Project documentation

🎯 Game Rules

Connect 4 is a classic strategy game where players take turns dropping colored pieces into a grid:

• Objective: Be the first to get 4 pieces in a row
• Winning Conditions: Horizontal, vertical, or diagonal connections
• Grid Size: 7 columns × 6 rows
• Turn-based: Players alternate dropping pieces
• Gravity Effect: Pieces fall to the lowest available position

🧮 Algorithm Details

The AI uses a sophisticated decision-making process:

• Minimax Algorithm: Evaluates all possible future game states
• Alpha-Beta Pruning: Optimizes search by eliminating inferior branches
• Evaluation Function: Scores board positions based on strategic value
• Depth Limitation: Searches 5 moves ahead for optimal performance balance

🤝 Contributing

Contributions are welcome! Here's how you can help:

1. Fork the repository
2. Create a feature branch (git checkout -b feature/amazing-feature)
3. Commit your changes (git commit -m 'Add amazing feature')
4. Push to the branch (git push origin feature/amazing-feature)
5. Open a Pull Request

🐛 Issues & Support

Found a bug or have a suggestion? Please:

1. Check existing issues
2. Create a new issue with detailed description
3. Include steps to reproduce (if applicable)

📄 License

This project is licensed under the MIT License - see the LICENSE file for details.

🙏 Acknowledgments

• Classic Connect 4 game concept by Milton Bradley
• Minimax algorithm implementation inspired by AI game theory
• Thanks to the Python and Flask communities

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Enjoy playing Connect 4 AI! 🎉

Challenge yourself against an intelligent opponent and improve your strategic skills.