C++
#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;
// Set up the game board as an array
vector<string> board = {"-", "-", "-", "-", "-", "-", "-", "-", "-"};
// Define a function to print the game board
void printBoard() {
cout << board[0] << " | " << board[1] << " | " << board[2] << endl;
cout << board[3] << " | " << board[4] << " | " << board[5] << endl;
cout << board[6] << " | " << board[7] << " | " << board[8] << endl;
}
// Define a function to handle a player's turn
void takeTurn(string player) {
cout << player << "'s turn." << endl;
cout << "Choose a position from 1-9: ";
int position;
cin >> position;
position -= 1;
while (position < 0 || position > 8 || board[position] != "-") {
cout << "Invalid input or position already taken. Choose a different position: ";
cin >> position;
position -= 1;
}
board[position] = player;
printBoard();
}
// Define a function to check if the game is over
string checkGameOver() {
// Check for a win
if ((board[0] == board[1] && board[1] == board[2] && board[0] != "-") ||
(board[3] == board[4] && board[4] == board[5] && board[3] != "-") ||
(board[6] == board[7] && board[7] == board[8] && board[6] != "-") ||
(board[0] == board[3] && board[3] == board[6] && board[0] != "-") ||
(board[1] == board[4] && board[4] == board[7] && board[1] != "-") ||
(board[2] == board[5] && board[5] == board[8] && board[2] != "-") ||
(board[0] == board[4] && board[4] == board[8] && board[0] != "-") ||
(board[2] == board[4] && board[4] == board[6] && board[2] != "-")) {
return "win";
}
// Check for a tie
else if (count(board.begin(), board.end(), "-") == 0) {
return "tie";
}
// Game is not over
else {
return "play";
}
}
// Define the main game loop
int main() {
printBoard();
string currentPlayer = "X";
bool gameOver = false;
while (!gameOver) {
takeTurn(currentPlayer);
string gameResult = checkGameOver();
if (gameResult == "win") {
cout << currentPlayer << " wins!" << endl;
gameOver = true;
} else if (gameResult == "tie") {
cout << "It's a tie!" << endl;
gameOver = true;
} else {
// Switch to the other player
currentPlayer = currentPlayer == "X" ? "O" : "X";
}
}
return 0;
}
Java
import java.util.Scanner;
public class TicTacToe {
// Set up the game board as an array
static String[] board = {"-", "-", "-", "-", "-", "-", "-", "-", "-"};
// Define a function to print the game board
static void printBoard() {
System.out.println(board[0] + " | " + board[1] + " | " + board[2]);
System.out.println(board[3] + " | " + board[4] + " | " + board[5]);
System.out.println(board[6] + " | " + board[7] + " | " + board[8]);
}
// Define a function to handle a player's turn
static void takeTurn(String player) {
Scanner scanner = new Scanner(System.in);
System.out.println(player + "'s turn.");
System.out.print("Choose a position from 1-9: ");
int position = scanner.nextInt() - 1;
while (position < 0 || position > 8 || !board[position].equals("-")) {
System.out.print("Invalid input or position already taken. Choose a different position: ");
position = scanner.nextInt() - 1;
}
board[position] = player;
printBoard();
}
// Define a function to check if the game is over
static String checkGameOver() {
// Check for a win
if ((board[0].equals(board[1]) && board[1].equals(board[2]) && !board[0].equals("-")) ||
(board[3].equals(board[4]) && board[4].equals(board[5]) && !board[3].equals("-")) ||
(board[6].equals(board[7]) && board[7].equals(board[8]) && !board[6].equals("-")) ||
(board[0].equals(board[3]) && board[3].equals(board[6]) && !board[0].equals("-")) ||
(board[1].equals(board[4]) && board[4].equals(board[7]) && !board[1].equals("-")) ||
(board[2].equals(board[5]) && board[5].equals(board[8]) && !board[2].equals("-")) ||
(board[0].equals(board[4]) && board[4].equals(board[8]) && !board[0].equals("-")) ||
(board[2].equals(board[4]) && board[4].equals(board[6]) && !board[2].equals("-"))) {
return "win";
}
// Check for a tie
else if (!String.join("", board).contains("-")) {
return "tie";
}
// Game is not over
else {
return "play";
}
}
// Define the main game loop
public static void main(String[] args) {
printBoard();
String currentPlayer = "X";
boolean gameOver = false;
while (!gameOver) {
takeTurn(currentPlayer);
String gameResult = checkGameOver();
if (gameResult.equals("win")) {
System.out.println(currentPlayer + " wins!");
gameOver = true;
} else if (gameResult.equals("tie")) {
System.out.println("It's a tie!");
gameOver = true;
} else {
// Switch to the other player
currentPlayer = currentPlayer.equals("X") ? "O" : "X";
}
}
}
}
Python
# Set up the game board as a list
board = ["-", "-", "-",
"-", "-", "-",
"-", "-", "-"]
# Define a function to print the game board
def print_board():
print(board[0] + " | " + board[1] + " | " + board[2])
print(board[3] + " | " + board[4] + " | " + board[5])
print(board[6] + " | " + board[7] + " | " + board[8])
# Define a function to handle a player's turn
def take_turn(player):
print(player + "'s turn.")
position = input("Choose a position from 1-9: ")
while position not in ["1", "2", "3", "4", "5", "6", "7", "8", "9"]:
position = input("Invalid input. Choose a position from 1-9: ")
position = int(position) - 1
while board[position] != "-":
position = int(input("Position already taken. Choose a different position: ")) - 1
board[position] = player
print_board()
# Define a function to check if the game is over
def check_game_over():
# Check for a win
if (board[0] == board[1] == board[2] != "-") or \
(board[3] == board[4] == board[5] != "-") or \
(board[6] == board[7] == board[8] != "-") or \
(board[0] == board[3] == board[6] != "-") or \
(board[1] == board[4] == board[7] != "-") or \
(board[2] == board[5] == board[8] != "-") or \
(board[0] == board[4] == board[8] != "-") or \
(board[2] == board[4] == board[6] != "-"):
return "win"
# Check for a tie
elif "-" not in board:
return "tie"
# Game is not over
else:
return "play"
# Define the main game loop
def play_game():
print_board()
current_player = "X"
game_over = False
while not game_over:
take_turn(current_player)
game_result = check_game_over()
if game_result == "win":
print(current_player + " wins!")
game_over = True
elif game_result == "tie":
print("It's a tie!")
game_over = True
else:
# Switch to the other player
current_player = "O" if current_player == "X" else "X"
# Start the game
play_game()
JavaScript
// Set up the game board as an array
let board = ["-", "-", "-", "-", "-", "-", "-", "-", "-"];
// Define a function to print the game board
function printBoard() {
console.log(`${board[0]} | ${board[1]} | ${board[2]}`);
console.log(`${board[3]} | ${board[4]} | ${board[5]}`);
console.log(`${board[6]} | ${board[7]} | ${board[8]}`);
}
// Define a function to handle a player's turn
function takeTurn(player) {
console.log(`${player}'s turn.`);
let position = prompt("Choose a position from 1-9:");
position -= 1;
while (position < 0 || position > 8 || board[position] !== "-") {
position = prompt("Invalid input or position already taken. Choose a different position:");
position -= 1;
}
board[position] = player;
printBoard();
}
// Define a function to check if the game is over
function checkGameOver() {
// Check for a win
if ((board[0] === board[1] && board[1] === board[2] && board[0] !== "-") ||
(board[3] === board[4] && board[4] === board[5] && board[3] !== "-") ||
(board[6] === board[7] && board[7] === board[8] && board[6] !== "-") ||
(board[0] === board[3] && board[3] === board[6] && board[0] !== "-") ||
(board[1] === board[4] && board[4] === board[7] && board[1] !== "-") ||
(board[2] === board[5] && board[5] === board[8] && board[2] !== "-") ||
(board[0] === board[4] && board[4] === board[8] && board[0] !== "-") ||
(board[2] === board[4] && board[4] === board[6] && board[2] !== "-")) {
return "win";
}
// Check for a tie
else if (!board.includes("-")) {
return "tie";
}
// Game is not over
else {
return "play";
}
}
// Define the main game loop
function main() {
printBoard();
let currentPlayer = "X";
let gameOver = false;
while (!gameOver) {
takeTurn(currentPlayer);
let gameResult = checkGameOver();
if (gameResult === "win") {
console.log(`${currentPlayer} wins!`);
gameOver = true;
} else if (gameResult === "tie") {
console.log("It's a tie!");
gameOver = true;
} else {
// Switch to the other player
currentPlayer = currentPlayer === "X" ? "O" : "X";
}
}
}
// Start the game
main();
Rules of the Game
- The game is to be played between two people (in this program between HUMAN and COMPUTER).
- One of the player chooses ‘O’ and the other ‘X’ to mark their respective cells.
- The game starts with one of the players and the game ends when one of the players has one whole row/ column/ diagonal filled with his/her respective character (‘O’ or ‘X’).
- If no one wins, then the game is said to be draw.
Implementation In our program the moves taken by the computer and the human are chosen randomly. We use rand() function for this. What more can be done in the program? The program is in not played optimally by both sides because the moves are chosen randomly. The program can be easily modified so that both players play optimally (which will fall under the category of Artificial Intelligence). Also the program can be modified such that the user himself gives the input (using scanf() or cin). The above changes are left as an exercise to the readers. Winning Strategy – An Interesting Fact If both the players play optimally then it is destined that you will never lose (“although the match can still be drawn”). It doesn’t matter whether you play first or second.In another ways - “ Two expert players will always draw ”. Isn’t this interesting ?
Cpp
#include <iostream>
#include <cstdlib>
#include <ctime>
#include <algorithm>
using namespace std;
#define COMPUTER 1
#define HUMAN 2
#define SIDE 3 // Length of the board
// Computer will move with 'O' and human with 'X'
#define COMPUTERMOVE 'O'
#define HUMANMOVE 'X'
// Function to show the current board status
void showBoard(char board[][SIDE]) {
cout << endl << "\t\t\t " << board[0][0] << " | " << board[0][1] << " | " << board[0][2] << endl;
cout << "\t\t\t--------------" << endl;
cout << "\t\t\t " << board[1][0] << " | " << board[1][1] << " | " << board[1][2] << endl;
cout << "\t\t\t--------------" << endl;
cout << "\t\t\t " << board[2][0] << " | " << board[2][1] << " | " << board[2][2] << endl << endl;
}
// Function to show the instructions
void showInstructions() {
cout << "\t\t\t Tic-Tac-Toe" << endl << endl;
cout << "Choose a cell numbered from 1 to 9 as below and play" << endl << endl;
cout << "\t\t\t 1 | 2 | 3" << endl;
cout << "\t\t\t--------------" << endl;
cout << "\t\t\t 4 | 5 | 6" << endl;
cout << "\t\t\t--------------" << endl;
cout << "\t\t\t 7 | 8 | 9" << endl << endl;
cout << "-\t-\t-\t-\t-\t-\t-\t-\t-\t-" << endl << endl;
}
// Function to initialise the game
void initialise(char board[][SIDE], int moves[]) {
srand(time(NULL));
for (int i = 0; i < SIDE; i++) {
for (int j = 0; j < SIDE; j++)
board[i][j] = ' ';
}
for (int i = 0; i < SIDE * SIDE; i++)
moves[i] = i;
random_shuffle(moves, moves + SIDE * SIDE);
}
// Function to declare the winner of the game
void declareWinner(int whoseTurn) {
if (whoseTurn == COMPUTER)
cout << "COMPUTER has won" << endl;
else
cout << "HUMAN has won" << endl;
}
// Function to check if any row is crossed with the same player's move
bool rowCrossed(char board[][SIDE]) {
for (int i = 0; i < SIDE; i++) {
if (board[i][0] == board[i][1] && board[i][1] == board[i][2] && board[i][0] != ' ')
return true;
}
return false;
}
// Function to check if any column is crossed with the same player's move
bool columnCrossed(char board[][SIDE]) {
for (int i = 0; i < SIDE; i++) {
if (board[0][i] == board[1][i] && board[1][i] == board[2][i] && board[0][i] != ' ')
return true;
}
return false;
}
// Function to check if any diagonal is crossed with the same player's move
bool diagonalCrossed(char board[][SIDE]) {
if (board[0][0] == board[1][1] && board[1][1] == board[2][2] && board[0][0] != ' ')
return true;
if (board[0][2] == board[1][1] && board[1][1] == board[2][0] && board[0][2] != ' ')
return true;
return false;
}
// Function to check if the game is over
bool gameOver(char board[][SIDE]) {
return (rowCrossed(board) || columnCrossed(board) || diagonalCrossed(board));
}
// Function to play Tic-Tac-Toe
void playTicTacToe(int whoseTurn) {
char board[SIDE][SIDE];
int moves[SIDE * SIDE];
initialise(board, moves);
showInstructions();
int moveIndex = 0, x, y;
while (gameOver(board) == false && moveIndex != SIDE * SIDE) {
if (whoseTurn == COMPUTER) {
x = moves[moveIndex] / SIDE;
y = moves[moveIndex] % SIDE;
board[x][y] = COMPUTERMOVE;
cout << "COMPUTER has put a " << COMPUTERMOVE << " in cell " << moves[moveIndex] + 1 << endl;
showBoard(board);
moveIndex++;
whoseTurn = HUMAN;
} else if (whoseTurn == HUMAN) {
x = moves[moveIndex] / SIDE;
y = moves[moveIndex] % SIDE;
board[x][y] = HUMANMOVE;
cout << "HUMAN has put a " << HUMANMOVE << " in cell " << moves[moveIndex] + 1 << endl;
showBoard(board);
moveIndex++;
whoseTurn = COMPUTER;
}
}
if (gameOver(board) == false && moveIndex == SIDE * SIDE)
cout << "It's a draw" << endl;
else {
if (whoseTurn == COMPUTER)
whoseTurn = HUMAN;
else if (whoseTurn == HUMAN)
whoseTurn = COMPUTER;
declareWinner(whoseTurn);
}
}
// Driver program
int main() {
playTicTacToe(COMPUTER);
return 0;
}
Java
public class TicTacToe {
private static final int COMPUTER = 1;
private static final int HUMAN = 2;
private static final int SIDE = 3; // Length of the board
// Computer will move with 'O' and human with 'X'
private static final char COMPUTERMOVE = 'O';
private static final char HUMANMOVE = 'X';
private char[][] board = new char[SIDE][SIDE];
private int[] moves = new int[SIDE * SIDE];
// Function to show the current board status
private void showBoard() {
System.out.println("\n\t\t\t " + board[0][0] + " | " + board[0][1] + " | " + board[0][2]);
System.out.println("\t\t\t--------------");
System.out.println("\t\t\t " + board[1][0] + " | " + board[1][1] + " | " + board[1][2]);
System.out.println("\t\t\t--------------");
System.out.println("\t\t\t " + board[2][0] + " | " + board[2][1] + " | " + board[2][2] + "\n");
}
// Function to show the instructions
private void showInstructions() {
System.out.println("\t\t\t Tic-Tac-Toe\n");
System.out.println("Choose a cell numbered from 1 to 9 as below and play\n");
System.out.println("\t\t\t 1 | 2 | 3");
System.out.println("\t\t\t--------------");
System.out.println("\t\t\t 4 | 5 | 6");
System.out.println("\t\t\t--------------");
System.out.println("\t\t\t 7 | 8 | 9\n");
System.out.println("-\t-\t-\t-\t-\t-\t-\t-\t-\t-\n");
}
// Function to initialise the game
private void initialise() {
for (int i = 0; i < SIDE; i++) {
for (int j = 0; j < SIDE; j++)
board[i][j] = ' ';
}
for (int i = 0; i < SIDE * SIDE; i++)
moves[i] = i;
// Shuffling moves
java.util.Collections.shuffle(java.util.Arrays.asList(moves));
}
// Function to declare the winner of the game
private void declareWinner(int whoseTurn) {
if (whoseTurn == COMPUTER)
System.out.println("COMPUTER has won");
else
System.out.println("HUMAN has won");
}
// Function to check if any row is crossed with the same player's move
private boolean rowCrossed() {
for (int i = 0; i < SIDE; i++) {
if (board[i][0] == board[i][1] && board[i][1] == board[i][2] && board[i][0] != ' ')
return true;
}
return false;
}
// Function to check if any column is crossed with the same player's move
private boolean columnCrossed() {
for (int i = 0; i < SIDE; i++) {
if (board[0][i] == board[1][i] && board[1][i] == board[2][i] && board[0][i] != ' ')
return true;
}
return false;
}
// Function to check if any diagonal is crossed with the same player's move
private boolean diagonalCrossed() {
if (board[0][0] == board[1][1] && board[1][1] == board[2][2] && board[0][0] != ' ')
return true;
if (board[0][2] == board[1][1] && board[1][1] == board[2][0] && board[0][2] != ' ')
return true;
return false;
}
// Function to check if the game is over
private boolean gameOver() {
return (rowCrossed() || columnCrossed() || diagonalCrossed());
}
// Function to play Tic-Tac-Toe
public void playTicTacToe(int whoseTurn) {
initialise();
showInstructions();
int moveIndex = 0, x, y;
while (!gameOver() && moveIndex != SIDE * SIDE) {
if (whoseTurn == COMPUTER) {
x = moves[moveIndex] / SIDE;
y = moves[moveIndex] % SIDE;
board[x][y] = COMPUTERMOVE;
System.out.println("COMPUTER has put a " + COMPUTERMOVE + " in cell " + (moves[moveIndex] + 1));
showBoard();
moveIndex++;
whoseTurn = HUMAN;
} else if (whoseTurn == HUMAN) {
x = moves[moveIndex] / SIDE;
y = moves[moveIndex] % SIDE;
board[x][y] = HUMANMOVE;
System.out.println("HUMAN has put a " + HUMANMOVE + " in cell " + (moves[moveIndex] + 1));
showBoard();
moveIndex++;
whoseTurn = COMPUTER;
}
}
if (!gameOver() && moveIndex == SIDE * SIDE)
System.out.println("It's a draw");
else {
if (whoseTurn == COMPUTER)
whoseTurn = HUMAN;
else if (whoseTurn == HUMAN)
whoseTurn = COMPUTER;
declareWinner(whoseTurn);
}
}
// Driver program
public static void main(String[] args) {
TicTacToe game = new TicTacToe();
game.playTicTacToe(COMPUTER);
}
}
Python3
import random
import time
# Constants for the game
COMPUTER = 1
HUMAN = 2
SIDE = 3
COMPUTERMOVE = 'O'
HUMANMOVE = 'X'
# Function to initialise the game / Tic-Tac-Toe board
def initialise():
board = [[' ' for _ in range(SIDE)] for _ in range(SIDE)]
moves = [i for i in range(SIDE*SIDE)]
random.shuffle(moves)
return board, moves
# Function to print the Tic-Tac-Toe board
def showBoard(board):
print("\n\n")
print("\t\t\t {} | {} | {} ".format(board[0][0], board[0][1], board[0][2]))
print("\t\t\t--------------")
print("\t\t\t {} | {} | {} ".format(board[1][0], board[1][1], board[1][2]))
print("\t\t\t--------------")
print("\t\t\t {} | {} | {} \n\n".format(board[2][0], board[2][1], board[2][2]))
# Function to show the instructions
def showInstructions():
print("\t\t\t Tic-Tac-Toe\n\n")
print("Choose a cell numbered from 1 to 9 as below and play\n\n")
print("\t\t\t 1 | 2 | 3 ")
print("\t\t\t--------------")
print("\t\t\t 4 | 5 | 6 ")
print("\t\t\t--------------")
print("\t\t\t 7 | 8 | 9 \n\n")
print("-\t-\t-\t-\t-\t-\t-\t-\t-\t-\n\n")
# Function to declare the winner of the game
def declareWinner(whoseTurn):
if whoseTurn == COMPUTER:
print("COMPUTER has won")
else:
print("HUMAN has won")
# Functions to check if any of the rows, columns, or diagonals have been crossed
def rowCrossed(board):
for i in range(SIDE):
if board[i][0] == board[i][1] and board[i][1] == board[i][2] and board[i][0] != ' ':
return True
return False
def columnCrossed(board):
for i in range(SIDE):
if board[0][i] == board[1][i] and board[1][i] == board[2][i] and board[0][i] != ' ':
return True
return False
def diagonalCrossed(board):
if board[0][0] == board[1][1] and board[1][1] == board[2][2] and board[0][0] != ' ':
return True
if board[0][2] == board[1][1] and board[1][1] == board[2][0] and board[0][2] != ' ':
return True
return False
# Function to check if the game is over
def gameOver(board):
return rowCrossed(board) or columnCrossed(board) or diagonalCrossed(board)
# Function to play Tic-Tac-Toe
def playTicTacToe(whoseTurn):
board, moves = initialise()
showInstructions()
moveIndex = 0
while not gameOver(board) and moveIndex != SIDE*SIDE:
if whoseTurn == COMPUTER:
x = moves[moveIndex] // SIDE
y = moves[moveIndex] % SIDE
board[x][y] = COMPUTERMOVE
print("COMPUTER has put a {} in cell {}".format(COMPUTERMOVE, moves[moveIndex]+1))
showBoard(board)
moveIndex += 1
whoseTurn = HUMAN
elif whoseTurn == HUMAN:
x = moves[moveIndex] // SIDE
y = moves[moveIndex] % SIDE
board[x][y] = HUMANMOVE
print("HUMAN has put a {} in cell {}".format(HUMANMOVE, moves[moveIndex]+1))
showBoard(board)
moveIndex += 1
whoseTurn = COMPUTER
if not gameOver(board) and moveIndex == SIDE*SIDE:
print("It's a draw")
else:
if whoseTurn == COMPUTER:
whoseTurn = HUMAN
elif whoseTurn == HUMAN:
whoseTurn = COMPUTER
declareWinner(whoseTurn)
# Driver function
if __name__ == "__main__":
# Let us play the game with COMPUTER starting first
playTicTacToe(COMPUTER)
JavaScript
const COMPUTER = 1;
const HUMAN = 2;
const SIDE = 3; // Length of the board
// Computer will move with 'O' and human with 'X'
const COMPUTERMOVE = 'O';
const HUMANMOVE = 'X';
// Function to show the current board status
function showBoard(board) {
console.log(`\n\t\t\t ${board[0][0]} | ${board[0][1]} | ${board[0][2]}`);
console.log(`\t\t\t--------------`);
console.log(`\t\t\t ${board[1][0]} | ${board[1][1]} | ${board[1][2]}`);
console.log(`\t\t\t--------------`);
console.log(`\t\t\t ${board[2][0]} | ${board[2][1]} | ${board[2][2]}\n`);
}
// Function to show the instructions
function showInstructions() {
console.log("\t\t\t Tic-Tac-Toe\n");
console.log("Choose a cell numbered from 1 to 9 as below and play\n");
console.log("\t\t\t 1 | 2 | 3");
console.log("\t\t\t--------------");
console.log("\t\t\t 4 | 5 | 6");
console.log("\t\t\t--------------");
console.log("\t\t\t 7 | 8 | 9\n");
console.log("-\t-\t-\t-\t-\t-\t-\t-\t-\t-\n");
}
// Function to initialise the game
function initialise(board, moves) {
for (let i = 0; i < SIDE; i++) {
board[i] = [];
for (let j = 0; j < SIDE; j++)
board[i][j] = ' ';
}
for (let i = 0; i < SIDE * SIDE; i++)
moves[i] = i;
// Shuffling moves
moves.sort(() => Math.random() - 0.5);
}
// Function to declare the winner of the game
function declareWinner(whoseTurn) {
if (whoseTurn === COMPUTER)
console.log("COMPUTER has won");
else
console.log("HUMAN has won");
}
// Function to check if any row is crossed with the same player's move
function rowCrossed(board) {
for (let i = 0; i < SIDE; i++) {
if (board[i][0] === board[i][1] && board[i][1] === board[i][2] && board[i][0] !== ' ')
return true;
}
return false;
}
// Function to check if any column is crossed with the same player's move
function columnCrossed(board) {
for (let i = 0; i < SIDE; i++) {
if (board[0][i] === board[1][i] && board[1][i] === board[2][i] && board[0][i] !== ' ')
return true;
}
return false;
}
// Function to check if any diagonal is crossed with the same player's move
function diagonalCrossed(board) {
if (board[0][0] === board[1][1] && board[1][1] === board[2][2] && board[0][0] !== ' ')
return true;
if (board[0][2] === board[1][1] && board[1][1] === board[2][0] && board[0][2] !== ' ')
return true;
return false;
}
// Function to check if the game is over
function gameOver(board) {
return (rowCrossed(board) || columnCrossed(board) || diagonalCrossed(board));
}
// Function to play Tic-Tac-Toe
function playTicTacToe(whoseTurn) {
const board = [];
const moves = Array.from({length: SIDE * SIDE});
initialise(board, moves);
showInstructions();
let moveIndex = 0, x, y;
while (!gameOver(board) && moveIndex !== SIDE * SIDE) {
if (whoseTurn === COMPUTER) {
x = Math.floor(moves[moveIndex] / SIDE);
y = moves[moveIndex] % SIDE;
board[x][y] = COMPUTERMOVE;
console.log(`COMPUTER has put a ${COMPUTERMOVE} in cell ${moves[moveIndex] + 1}`);
showBoard(board);
moveIndex++;
whoseTurn = HUMAN;
} else if (whoseTurn === HUMAN) {
x = Math.floor(moves[moveIndex] / SIDE);
y = moves[moveIndex] % SIDE;
board[x][y] = HUMANMOVE;
console.log(`HUMAN has put a ${HUMANMOVE} in cell ${moves[moveIndex] + 1}`);
showBoard(board);
moveIndex++;
whoseTurn = COMPUTER;
}
}
if (!gameOver(board) && moveIndex === SIDE * SIDE)
console.log("It's a draw");
else {
if (whoseTurn === COMPUTER)
whoseTurn = HUMAN;
else if (whoseTurn === HUMAN)
whoseTurn = COMPUTER;
declareWinner(whoseTurn);
}
}
// Driver program
playTicTacToe(COMPUTER);
- Output:
Tic-Tac-Toe
Choose a cell numbered from 1 to 9 as below and play
1 | 2 | 3
--------------
4 | 5 | 6
--------------
7 | 8 | 9
- - - - - - - - - -
COMPUTER has put a O in cell 6
| |
--------------
| | O
--------------
| |
HUMAN has put a X in cell 7
| |
--------------
| | O
--------------
X | |
COMPUTER has put a O in cell 5
| |
--------------
| O | O
--------------
X | |
HUMAN has put a X in cell 1
X | |
--------------
| O | O
--------------
X | |
COMPUTER has put a O in cell 9
X | |
--------------
| O | O
--------------
X | | O
HUMAN has put a X in cell 8
X | |
--------------
| O | O
--------------
X | X | O
COMPUTER has put a O in cell 4
X | |
--------------
O | O | O
--------------
X | X | O
COMPUTER has won
- An Interesting Variant of this game As said above, if two experienced players are playing the Tic-Tac-Toe, then the game will always draw. There is another viral variant of this game- Ultimate Tic-Tac-Toe, which aims to make the normal Tic-Tac-Toe more interesting and less predictable. Have a look at the game here- Link1 Link2 The above article implements simple Tic-Tac-Toe where moves are randomly made. Please refer below article to see how optimal moves are made. Minimax Algorithm in Game Theory | Set 3 (Tic-Tac-Toe AI – Finding optimal move) Great discussions on the “winning/never losing” strategy Quora Wikihow
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