Instructions

Modify the program so that the computer will generate moves for the
‘O' player (it must continue to accept user input for ‘X'). A simple way to do this is to use a random value between 0 and 9 to generate moves for ‘O'.

currMove = (int)(Math.random() * 9) + 1;

You will have to ensure, of course, that the computer does not generate a move for a square that is already occupied. Another simple way to generate moves is to simply move to the first unoccupied square.

Also I need explain in words (as clearly and precisely as possible) any improvements you made to the program.

Any other improvement to make this program looks better please sent me in a different attach.

The Program

/**
* Homework Assignment #1 -- Working With Two-Dimensional Arrays (Tic-Tac-Toe)
* CPS , Section [[Put your section number here]]
*
* @author [[Put your name here]]
* @version 1.1 [[Put current date here]]
*/
import java.util.Scanner;

public class Hmwk1 {

public static final char SPACE = ' ';
// Tic-tac-toe board showing move numbers
public static final char[][] MOVE_INFO = {{'1', '2', '3'},
{'4', '5', '6'},
{'7', '8', '9'}};

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

char[][] board = new char[3][3];
char currPlayer = 'X';

fill2D(board, SPACE);
printBoard(MOVE_INFO);
while (!gameOver(board)) {
System.err.print("Move for " + currPlayer + "? ");
int currMove = in.nextInt();
makeMove(currPlayer, currMove, board);
printBoard(board);
currPlayer = nextPlayer(currPlayer);
}
reportResults(board);
}

/**
* Fill a given two-dimensional character array with a given
* character
*
* @param a the array to fill
* @param c the character to use
*/
public static void fill2D(char[][] a, char c) {
for (int i = 0; i < a.length; i++) {
for (int j = 0; j < a[i].length; j++) {
a[i][j] = c;
}
}
}

public static final String VERT = " * * ";
public static final String HORZ = "***********";

/**
* Print the contents of an array representing a tic-tac-toe
* board
*
* @param board the board configuration to be printed
*/
public static void printBoard(char[][] board) {
System.out.println();
for (int i = 0; i < board.length; i++) {
System.out.println(VERT);
for (int j = 0; j < board[i].length; j++) {
System.out.print(" " + board[i][j] + " ");
if (j < board[i].length - 1) {
System.out.print("*");
} else {
System.out.println();
}
}
System.out.println(VERT);
if (i < board.length - 1) {
System.out.println(HORZ);
}
}
System.out.println();
}

/**
* Determine if the game is over; i.e., if a player has won or if
* there are no more moves possible
*
* @param board current board configuration
* @return true if game is over, false otherwise
*/
public static boolean gameOver(char[][] board) {
return noMovesLeft(board)
|| isWinner('X', board)
|| isWinner('O', board);
}

/**
* Determine if no more moves are possible; i.e., if there
* are no more SPACE's left in the board array
*
* @param board the current board configuration
* @return true if there are no more legal moves, false otherwise
*/
public static boolean noMovesLeft(char[][] board) {
for (int i = 0; i < board.length; i++) {
for (int j = 0; j < board[i].length; j++) {
if (board[i][j] == SPACE) {
return false;
}
}
}
return true;
}

/**
* Determine if a given player is a winner; i.e., has 3 marks in a
* row, either horizontally, vertically, or diagonally
*
* @param player the player to check
* @param board the current board configuration
* @return true if player has 3 marks in a row, false otherwise
*/
public static boolean isWinner(char player, char[][] board) {
// check rows (horizontal)
for (int row = 0; row < 3; row++) {
if (board[row][0] == player && board[row][1] == player
&& board[row][2] == player) {
return true;
}
}
// check cols (vertical)
for (int col = 0; col < 3; col++) {
if (board[0][col] == player && board[1][col] == player
&& board[2][col] == player) {
return true;
}
}
// check diagonals
if (board[0][0] == player && board[1][1] == player
&& board[2][2] == player) {
return true;
} else if (board[0][2] == player && board[1][1] == player
&& board[2][0] == player) {
return true;
} else {
return false;
}
}

/**
* Mark the specified move for the specified player on the given
* board configuration (move == 1 => [0][0], move == 2 => [0][1],
* move == 3 => [0][2], move == 4 => [1][0], move == 5 => [1][1],
* move == 6 => [1][2], move == 7 => [2][0], move == 8 => [2][1],
* move == 9 => [2][2])
*
* @param player the player making the move
* @param move the move to be made
* @param board the current board configuration
*/
public static void makeMove(char player, int move, char[][] board) {
int row = (move - 1) / board.length;
int col = (move - 1) % board[row].length;
board[row][col] = player;
}

/**
* Determine the next player, for cycling X, then O, then X, etc.
*
* @param current the current player ('X' or 'O')
* @return the next player to play ('O' or 'X')
*/
public static char nextPlayer(char current) {
if (current == 'X') {
return 'O';
} else {
return 'X';
}
}

/**
* Report the results of the game, whether X or O won or the game
* ended in a tie.
*
* @param board the board configuration to be described
*/
public static void reportResults(char[][] board) {
if (isWinner('O', board)) {
System.out.println("O is the winner!");
} else if (isWinner('X', board)) {
System.out.println("X is the winner!");
} else {
System.out.println("The game ends in a tie.");
}
}

}