I need help writing a Java program for a game of TicTacToe. It is a two player g
ID: 3685859 • Letter: I
Question
I need help writing a Java program for a game of TicTacToe.
It is a two player game, and the rules are as follows:
1. The game begins with an empty, 3 × 3 grid.
2. The two players then take turns placing a mark in an empty grid cell. Player O will use the ‘O’ (letter ‘O’, not zero) mark and Player X will use the ‘X’ mark. Player O moves first.
3. The game is over in either case: (i) one player has 3 marks in a sequence (vertically, horizontally, diagonally, or anti-diagonally), or (ii) there are no empty cells left.
Note: There are four cases: (i) Player O has won; (ii) Player X has won; (iii) the game is a draw; (iv) the game can still continue.
Note: Use the Scanner class for keyboard input.
Below shows a run of the game, a sample output where Player O moved first and won the game by placing 3 ‘O’s in second row the game grid.
Explanation / Answer
Hi below i have written the sample TicTacToe game for your reference,
Main class:
package com.javadb.tictactoe;
/**
*
* @author www.javadb.com
*/
public class Main {
public void play() {
TicTacToe game = new TicTacToe();
System.out.println("Welcome! Tic Tac Toe is a two player game.");
System.out.print("Enter player one's name: ");
game.setPlayer1(game.getPrompt());
System.out.print("Enter player two's name: ");
game.setPlayer2(game.getPrompt());
boolean markerOk = false;
while (!markerOk) {
System.out.print("Select any letter as " + game.getPlayer1() + "'s marker: ");
String marker = game.getPrompt();
if (marker.length() == 1 &&
Character.isLetter(marker.toCharArray()[0])) {
markerOk = true;
game.setMarker1(marker.toCharArray()[0]);
} else {
System.out.println("Invalid marker, try again");
}
}
markerOk = false;
while (!markerOk) {
System.out.print("Select any letter as " + game.getPlayer2() + "'s marker: ");
String marker = game.getPrompt();
if (marker.length() == 1 &&
Character.isLetter(marker.toCharArray()[0])) {
markerOk = true;
game.setMarker2(marker.toCharArray()[0]);
} else {
System.out.println("Invalid marker, try again");
}
}
boolean continuePlaying = true;
while (continuePlaying) {
game.init();
System.out.println();
System.out.println(game.getRules());
System.out.println();
System.out.println(game.drawBoard());
System.out.println();
String player = null;
while (!game.winner() && game.getPlays() < 9) {
player = game.getCurrentPlayer() == 1 ? game.getPlayer1() : game.getPlayer2();
boolean validPick = false;
while (!validPick) {
System.out.print("It is " + player + "'s turn. Pick a square: ");
String square = game.getPrompt();
if (square.length() == 1 && Character.isDigit(square.toCharArray()[0])) {
int pick = 0;
try {
pick = Integer.parseInt(square);
} catch (NumberFormatException e) {
//Do nothing here, it'll evaluate as an invalid pick on the next row.
}
validPick = game.placeMarker(pick);
}
if (!validPick) {
System.out.println("Square can not be selected. Retry");
}
}
game.switchPlayers();
System.out.println();
System.out.println(game.drawBoard());
System.out.println();
}
if (game.winner()) {
System.out.println("Game Over - " + player + " WINS!!!");
} else {
System.out.println("Game Over - Draw");
}
System.out.println();
System.out.print("Play again? (Y/N): ");
String choice = game.getPrompt();
if (!choice.equalsIgnoreCase("Y")) {
continuePlaying = false;
}
}
}
/**
* @param args the command line arguments
*/
public static void main(String[] args) {
Main main = new Main();
main.play();
}
}
Code for the TicTacToe class:
package com.javadb.tictactoe;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
/**
*
* @author www.javadb.com
*/
public class TicTacToe {
private char[][] board = new char[3][3];
private String player1;
private String player2;
private int currentPlayer;
private char marker1;
private char marker2;
private int plays;
private BufferedReader reader =
new BufferedReader(new InputStreamReader(System.in));
protected void init() {
int counter = 0;
for (int i = 0; i < 3; i++) {
for (int i1 = 0; i1 < 3; i1++) {
board[i][i1] = Character.forDigit(++counter, 10);
}
}
currentPlayer = 1;
plays = 0;
}
protected void switchPlayers() {
if (getCurrentPlayer() == 1) {
setCurrentPlayer(2);
} else {
setCurrentPlayer(1);
}
setPlays(getPlays() + 1);
}
protected boolean placeMarker(int play) {
for (int i = 0; i < 3; i++) {
for (int i1 = 0; i1 < 3; i1++) {
if (board[i][i1] == Character.forDigit(play, 10)) {
board[i][i1] = (getCurrentPlayer() == 1) ? getMarker1() : getMarker2();
return true;
}
}
}
return false;
}
protected boolean winner() {
//Checking rows
char current = ' ';
for (int i = 0; i < 3; i++) {
int i1 = 0;
for (i1 = 0; i1 < 3; i1++) {
if (!Character.isLetter(board[i][i1])) {
break;
}
if (i1 == 0) {
current = board[i][i1];
} else if (current != board[i][i1]) {
break;
}
if (i1 == 2) {
//Found winner
return true;
}
}
}
//Checking columns
for (int i = 0; i < 3; i++) {
current = ' ';
int i1 = 0;
for (i1 = 0; i1 < 3; i1++) {
if (!Character.isLetter(board[i1][i])) {
break;
}
if (i1 == 0) {
current = board[i1][i];
} else if (current != board[i1][i]) {
break;
}
if (i1 == 2) {
//Found winner
return true;
}
}
}
//Checking diagonals
current = board[0][0];
if (Character.isLetter(current) && board[1][1] == current && board[2][2] == current) {
return true;
}
current = board[2][0];
if (Character.isLetter(current) && board[1][1] == current && board[0][2] == current) {
return true;
}
return false;
}
protected String getRules() {
StringBuilder builder = new StringBuilder();
builder.append("Players take turns marking a square. Only squares ");
builder.append("not already marked can be picked. Once a player has ");
builder.append("marked three squares in a row, the player wins! If all squares ");
builder.append("are marked and no three squares are the same, a tie game is declared. ");
builder.append("Have Fun! ");
return builder.toString();
}
protected String getPrompt() {
String prompt = "";
try {
prompt = reader.readLine();
} catch (IOException ex) {
ex.printStackTrace();
}
return prompt;
}
protected String drawBoard() {
StringBuilder builder = new StringBuilder("Game board: ");
for (int i = 0; i < 3; i++) {
for (int i1 = 0; i1 < 3; i1++) {
builder.append("[" + board[i][i1] + "]");
}
builder.append(" ");
}
return builder.toString();
}
public int getCurrentPlayer() {
return currentPlayer;
}
public void setCurrentPlayer(int currentPlayer) {
this.currentPlayer = currentPlayer;
}
public char getMarker1() {
return marker1;
}
public void setMarker1(char marker1) {
this.marker1 = marker1;
}
public char getMarker2() {
return marker2;
}
public void setMarker2(char marker2) {
this.marker2 = marker2;
}
public int getPlays() {
return plays;
}
public void setPlays(int plays) {
this.plays = plays;
}
public String getPlayer1() {
return player1;
}
public void setPlayer1(String player1) {
this.player1 = player1;
}
public String getPlayer2() {
return player2;
}
public void setPlayer2(String player2) {
this.player2 = player2;
}
}