gameai.java

import java.util.Scanner;

public class gameai {

    public static void drawBoard(int[] matrix) {
        System.out.println("Current State of Board:\n");
        for (int i = 0; i < 9; i++) {
            if (i > 0 && i % 3 == 0) {
                System.out.println("\n");
            }
            if (matrix[i] == 0) {
                System.out.print("- ");
            } else if (matrix[i] == 1) {
                System.out.print("O ");
            } else if (matrix[i] == -1) {
                System.out.print("X ");
            }
        }
        System.out.println("\n");
    }

    public static void userTurn(int[] matrix) {
        Scanner scanner = new Scanner(System.in);
        while (true) {
            System.out.print("Enter X's position from [1...9]: ");
            int pos = scanner.nextInt();
            if (pos >= 1 && pos <= 9 && matrix[pos - 1] == 0) {
                matrix[pos - 1] = -1; // Player's move marked with -1
                break;
            } else {
                System.out.println("Illegal Move! Try again.");
            }
        }
    }

    public static int minimax(int[] matrix, int player) {
        int winner = analyzeBoard(matrix);
        if (winner != 0) {
            return winner * player;
        }

        int pos = -1;
        int value = -2;
        for (int i = 0; i < 9; i++) {
            if (matrix[i] == 0) {
                matrix[i] = player;
                int score = -minimax(matrix, -player);
                if (score > value) {
                    value = score;
                    pos = i;
                }
                matrix[i] = 0;
            }
        }

        if (pos == -1) {
            return 0;
        }
        return value;
    }

    public static void computerTurn(int[] matrix) {
        int pos = -1;
        int value = -2;
        for (int i = 0; i < 9; i++) {
            if (matrix[i] == 0) {
                matrix[i] = 1; 
                int score = -minimax(matrix, -1);
                matrix[i] = 0;
                if (score > value) {
                    value = score;
                    pos = i;
                }
            }
        }
        matrix[pos] = 1;
    }

    public static int analyzeBoard(int[] matrix) {
        int[][] cb = {
                { 0, 1, 2 }, { 3, 4, 5 }, { 6, 7, 8 },
                { 0, 3, 6 }, { 1, 4, 7 }, { 2, 5, 8 },
                { 0, 4, 8 }, { 2, 4, 6 }
        };

        for (int i = 0; i < 8; i++) {
            if (matrix[cb[i][0]] != 0 &&
                    matrix[cb[i][0]] == matrix[cb[i][1]] &&
                    matrix[cb[i][0]] == matrix[cb[i][2]]) {
                return matrix[cb[i][2]];
            }
        }
        return 0;
    }

    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        int[] matrix = new int[9];

        System.out.println("Computer : O Vs. You : X");
        System.out.print("Enter to play 1(st) or 2(nd): ");
        int player = scanner.nextInt();

        for (int i = 0; i < 9; i++) {
            if (analyzeBoard(matrix) != 0) {
                break;
            }
            if ((i + player) % 2 == 0) {
                computerTurn(matrix);
            } else {
                drawBoard(matrix); 
                userTurn(matrix); 
            }
        }

        int winner = analyzeBoard(matrix);
        drawBoard(matrix); 
        if (winner == 0) {
            System.out.println("Draw!!!");
        } else if (winner == -1) {
            System.out.println("X Wins!!! You Win!!!");
        } else if (winner == 1) {
            System.out.println("X Loses!!! O Wins!!!");
        }

        scanner.close();
    }
}