Question

Write a program for playing tic tac toe. Two players take turns marking an available cell in a 3 X 3 grid with their respective tokens (either X or O). When one player has placed the three tokens in a horizontal, vertical, or diagonal row on the grid, the game is over and that player has won. A draw occurs when all the cells on the grid have been filled with tokens and neither player has achieved a win. When a token is entered, the program redisplays the board on the console and determines the status of the game. (Win or Draw).

Answer 1

Answer:

import java.util.*;

public class tictactoe{

  //array to store values inserted in the bord

  static char[][] board = {{' ',' ',' '},{' ',' ',' '},{' ',' ',' '}};

  //method to display board

  public static void display(){

      System.out.println("-------------");

      for(int i=0;i<3;i++){

          for(int j=0;j<3;j++){

              System.out.print("|");

              if(board[i][j] != ' ')

                  System.out.print(board[i][j]);

          }

          System.out.println("|");

      }

      System.out.println("-------------");

  }

  //method for player1 to make choice

  public static void player1(){

      Scanner in = new Scanner(System.in);

      System.out.print("Enter a row for player X: ");

      int row = in.nextInt();

      System.out.print("Enter a column for player X: ");

      int col = in.nextInt();

      //if the value are not valid and not between 0-2

      if(row > 2 || row < 0 || col > 2 || col < 0){

          System.out.println("Invalid Choice");

          player1();

      }

      //if selected position is empty

      else if(board[row][col] == ' '){

          board[row][col] = 'X';

          check('X',row,col);

          player2();

      }

      //if selected position is not empty

      else{

          System.out.println("Already filed, Enter another choice");

          player1();

      }

  }

  //method for player2 to make choice

  public static void player2(){

      Scanner in = new Scanner(System.in);

      System.out.print("Enter a row for player O: ");

      int row = in.nextInt();

      System.out.print("Enter a column for player O: ");

      int col = in.nextInt();

      //if the value are not valid and not between 0-2

      if(row > 2 || row < 0 || col > 2 || col < 0){

          System.out.println("Invalid Choice");

          player2();

      }

      //if selected position is empty

      else if(board[row][col] == ' '){

          board[row][col] = 'O';

          check(')',row,col);

          player1();

      }

      //if selected position is not empty

      else{

          System.out.println("Already filed, Enter another choice");

          player2();

      }

  }

  //method to check whether a player has won

  public static void check(char s, int row, int col){

      display();

      //check row has same 3 values

      int count = 0;

      for(int i=0;i<3;i++){

          if(board[row][i] == s)

              count++;

      }

      if(count == 3){

          System.out.println(s + " player won");

          System.exit(0);

      }

      //checking column has same 3 values

      count = 0;

      for(int i=0;i<3;i++){

          if(board[i][col] == s)

              count++;

      }

      if(count == 3){

          System.out.println(s + " player won");

          System.exit(0);

      }

      //checking first diagonal has same 3 values

      count = 0;

      for(int i=0;i<3;i++){

          if(board[i][i] == s)

              count++;

      }

      if(count == 3){

          System.out.println(s + " player won");

          System.exit(0);

      }

      //checking second diagonal has same 3 values

      count = 0;

      for(int i=0;i<3;i++){

          if(board[i][2-i] == s)

              count++;

      }

      if(count == 3){

          System.out.println(s + " player won");

          System.exit(0);

      }

      //checking whether all places are filled

      count = 0;

      for(int i=0;i<3;i++)

          for(int j=0;j<3;j++)

              if(board[i][j] == ' ')

                  count++;

      if(count == 0){

          System.out.println("Game tied");

          System.exit(0);

      }

  }

  public static void main(String[] args){

      display();

      player1();

  }

}

Explanation: