Building an Unbeatable Tic-Tac-Toe Bot with Go and WebAssembly

The MiniMax Algorithm

The MiniMax algorithm is a decision rule used in Artificial Intelligence (AI) to minimize the possible loss for a worst-case scenario. In the context of tic-tac-toe, our bot will use this algorithm to choose the path that gives the opponent the lowest opportunity to win.

Implementing MiniMax in Go

We’ll start by creating a new Go file called tictactoe.go. In this file, we’ll define a function called GetNextMove that takes the current game state as input and returns the best move for the bot.

package main

import (
"fmt"
)

func GetNextMove(state [3][3]int) (int, int) {
    // Implement the MiniMax algorithm here
    // For example, we can start by iterating through all possible moves
    for i := 0; i < 3; i++ {
        for j := 0; j < 3; j++ {
            if state[i][j] == 0 {
                // Make a move and evaluate the resulting game state
                newState := state
                newState[i][j] = 1
                // Evaluate the new state using the MiniMax algorithm
                //...
            }
        }
    }
}

Integrating with React using WebAssembly

To integrate our Go code with a React front-end, we’ll use WebAssembly. We’ll create a new React app and then import our Go code as a WebAssembly module.

import React from 'eact';
import ReactDOM from 'eact-dom';
import { Go } from './go';

const App = () => {
    const [gameState, setGameState] = React.useState([[0, 0, 0], [0, 0, 0], [0, 0, 0]]);

    const handleMove = (x, y) => {
        // Call the GetNextMove function from our Go code
        const nextMove = Go.GetNextMove(gameState);
        // Update the game state with the bot's move
        setGameState(nextMove);
    };

    return (
        <div>
            <h1>Tic-Tac-Toe Bot</h1>
            <ul>
                {gameState.map((row, i) => (
                    <li key={i}>
                        {row.map((cell, j) => (
                            <span key={j}>{cell === 0? '-' : cell === 1? 'X' : 'O'}</span>
                        ))}
                    </li>
                ))}
            </ul>
            <button onClick={() => handleMove(0, 0)}>Make a move</button>
        </div>
    );
};

ReactDOM.render(<App />, document.getElementById('root'));

In this example, we’ve created a simple React app that displays the game state as a 3×3 grid. When the user clicks the “Make a move” button, we call the GetNextMove function from our Go code to get the bot’s next move, and then update the game state accordingly.