Connect Four in Python

This repository contains two versions of a Connect Four game implemented in Python:

1. Connect4 (Two Human Players)
2. Connect4 (AI Player) featuring a minimax-based computer opponent.

Both versions retain the core Connect Four mechanics but differ in how the second player’s moves are decided.

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Table of Contents

1. Overview
2. Features
   • Connect4 (Two Human Players)
   • Connect4 (AI Player)
3. Gameplay Rules
4. How to Run
5. File Structure
6. Future Enhancements

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Overview

Connect Four is a classic two-player game where you drop discs into one of the columns, attempting to line up four of your discs in a row before your opponent does. This repository offers:

• A traditional 2-player mode (Human vs. Human).
• An AI-enhanced mode (Human vs. Computer) using minimax with alpha-beta pruning, leveraging the random and math libraries.

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Features

Connect4 (Two Human Players)

• Board Generation
  Creates a 6×7 grid by default using generateField(). You can customize row and column sizes via parameters.

• Turn-Based Input
  Players (Player 0 = "R", Player 1 = "Y") alternate columns to drop their discs.

• Winning/Tie Checks
  After each move, checks if 4 in a row is formed (horizontally, vertically, or diagonally). If the board fills up, the result is a tie.

• Simple Board Drawing
  Displays columns separated by " | " with a dashed line after each row.

Connect4 (AI Player)

• AI Opponent
  In this version, Player 1 is replaced with an AI that uses a minimax algorithm for strategic column selection.

• Scoring & Evaluation
  The AI’s decision-making:

  • Considers potential winning moves.
  • Evaluates board states based on the number of aligned discs and the center-column advantage.
  • Searches multiple moves ahead (controlled by a depth parameter).

• Random Element
  Some fallback decisions may involve the random library to break ties among equally strong moves.

• Still Allows Board Customization
  The same row and column parameters can be adjusted for custom board sizes.

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Gameplay Rules

1. Objective
   Get four of your discs in a row before your opponent does. The row can be:

   • Horizontal
   • Vertical
   • Diagonal (descending or ascending)

2. Turn Order

   • Player 0 goes first with discs labeled "R".
   • Player 1 uses discs labeled "Y".
   • In the AI version, Player 1 is controlled by the minimax algorithm.

3. Placement Rules

   • Choose a column (1-based index).
   • The disc drops in the lowest empty row of that column.
   • If the column is full, you’ll be asked to choose another one.

4. Ending Conditions

   • A player achieves 4 in a row → that player wins immediately.
   • The grid is full with no winner → tie.

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How to Run

1. Clone the Repository:

   git clone https://github.com/Sabdikay/Connect4.git
   cd Connect4

2. Run the Desired Version:

   • Two Human Players:

     python Connect4.py

   • AI Player:

     python Connect4(AI player).py

3. Play the Game:

   • Input the column when prompted.
   • For the AI version, watch as the computer chooses an optimal (or near-optimal) move.

4. Customize Board Dimensions (Optional):

   • In either file, you can call startGame(nrow, ncol) with custom values:

     startGame(8, 9)  # 8 rows, 9 columns

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File Structure

Connect4/
├── Connect4.py            # Two Human Players
├── Connect4(AI player).py # Computer Player using Minimax
├── README.md              # This README

• Connect4.py
  Implements the standard 2-player logic.

• Connect4(AI player).py
  Contains the AI logic using minimax with helper functions (evaluateField, minimax, etc.).

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Future Enhancements

• More Sophisticated AI: Add a deeper search or a weighting system for more advanced strategic play.
• GUI Version: Integrate a library like Pygame or tkinter for a graphical interface.
• Logging & Statistics: Track win rates, average game length, and other useful data.

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Enjoy your game of Connect Four, whether you challenge a friend or our AI opponent!