Create a Tic Tac Toe game. In this game, two players alternate placing Xs and Os
ID: 3669078 • Letter: C
Question
Create a Tic Tac Toe game. In this game, two players alternate placing Xs and Os into a grid until one player has three matching symbols in a row, horizontally, vertically, or diagonally. Create a game in which the user is presented with a three-by-three grid containing the digits 1 through 9. When the user chooses a position by typing a number, place an X in the appropriate spot. Generate a random number for the position where the computer will place an O. Do not allow the player or the computer to place a symbol where one has already been placed. When either the player or computer has three symbols in a row, declare a winner; if all positions have been exhausted and no one has three symbols in a row, declare a tie. Save the game as TicTacToe.java
I am specifically learning about 2 dimensional arrays, but I cannot figure out how to make this program work.
Explanation / Answer
//class tictactoe
package tictactoe;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
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));//read input from user
protected void init() {// initialize the 3x3 to numbered form 1 to 9
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() {//switch the players one after one
if (getCurrentPlayer() == 1) {
setCurrentPlayer(2);
} else {
setCurrentPlayer(1);
}
setPlays(getPlays() + 1);
}
protected boolean placeMarker(int play) {//placing marker or symbol where user specified location
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("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. ");
return builder.toString();
}
protected String getPrompt() {//taking input
String prompt = "";
try {
prompt = reader.readLine();
} catch (IOException ex) {
ex.printStackTrace();
}
return prompt;
}
protected String drawBoard() {// display the matrix or board
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;
}
}
//class game implementation
package tictactoe;
public class Imptictactoe{
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());
game.setPlayer2("computer");
game.setMarker1('x');
game.setMarker2('o');
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;
String square;
while (!validPick) {
if(game.getCurrentPlayer==1){
System.out.print("It is " + player + "'s turn. Pick a square: ");
square = game.getPrompt();
}else
{
Random r=new Random();
int i = rn.nextInt() % 10;
square=(String)i;}
}
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;
}
}
}
public static void main(String[] args) {
Imptictactoe main = new Imptictactoe();
main.play();
}
}