Tic-Tac-Toe with AI

A C++ implementation of the classic Tic-Tac-Toe game featuring an unbeatable AI opponent using the Minimax algorithm.

Project Overview

This project was created as a learning exercise to understand:

• Implementation of the Minimax algorithm
• Game state management
• Basic AI decision making
• C++ programming concepts

Features

• Player vs AI gameplay
• Unbeatable AI opponent
• Clean console interface
• Move validation
• Available moves display
• Option to play multiple games

How to Run

1. Ensure you have a C++ compiler installed (g++ recommended)
2. Compile the code:

g++ game.cpp -o main

3. Run the executable:

./main.exe

Understanding the Minimax Algorithm

The Minimax algorithm used in this project is a decision-making algorithm that plays a crucial role in the game's AI. Here's how it works:

Basic Concept

Minimax is a recursive algorithm that helps the AI determine the best possible move by:

• Maximizing the AI's chances of winning
• Minimizing the player's chances of winning

How it Works in This Project

1. Scoring System:

   • Win: +10 for AI, -10 for Human
   • Draw: 0
   • Loss: -10 for AI, +10 for Human

2. Algorithm Flow:

   • The algorithm simulates all possible moves
   • For each move, it recursively evaluates future game states
   • The AI (maximizer) tries to get the highest score
   • The Human (minimizer) is assumed to play optimally to get the lowest score

3. Implementation Details:

int minimax(vector<vector<char>>& board, int depth, bool is_ai) {
    // Base cases: game over or board full
    if (game_over(board)) return is_ai ? -10 : 10;
    if (depth == 9) return 0;

    // Recursive case
    int best_score = is_ai ? -9999 : 9999;
    for (each empty cell) {
        make move
        evaluate score
        undo move
        update best_score
    }
    return best_score;
}

Resources Used

• C++ Standard Library
• Minimax Algorithm Documentation
• Game Theory Concepts