The Class below uses a 2-D array board. board[0][0] is the top left corner and board[2][2] is the bottom right. If a spot is free to be chosen by X or O, there is a zero there. If X chooses the center spot, then board[1][1] is set to 1. If O chooses the top right spot, then board[0][2]=-1.
You need to finish the three methods that check for a "Cat's Game" (no winner, no spaces availible) or a win from either X or O
For 8 points, use no loops. For 9 points use loops. For 10 points use embedded loops. For 11 points change the logic in the ConsoleTTT so you can play more than one game without restarting the main method.
java.lang.Object TTTBoard
public class TTTBoard
Class TTTBoard is one way to represent a tic tac toe board.
| Constructor Summary | |
|---|---|
TTTBoard()
Constructor for objects of class TTTBoard |
|
| Method Summary | |
|---|---|
boolean |
checkForCatsGame()
checks for Cats Game by looking for board loctions that have a "0" |
boolean |
checkForOWin()
checks for an O win by looking for one of 8 ways that there are 3 -1's in a row. |
boolean |
checkForXWin()
checks for an X win by looking for one of 8 ways that there are 3 1's in a row. |
void |
clear()
clear sets the board to the starting position |
int |
get(int row,
int col)
get returns the contents of a board position |
boolean |
set(int row,
int col,
int value)
sets the contents of a board position to either 1 or -1 |
java.lang.String |
showBoard()
a "String-Graphics" represention of the entire tic tac toe board |
java.lang.String |
symbol(int row,
int col)
coverts the numerical contents of a board position to a String represention |
| Methods inherited from class java.lang.Object |
|---|
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait |
/**
* Class TTTBoard is one way to represent a tic tac toe board.
*
* @author Chris Thiel,OFMCap
* @version 28 Oct 2007
*/
public class TTTBoard
{
/** instance variables - board
*
* 1 = X's
* 0 = unchosen
* -1= O's
*/
private int [][] board;
private final int X=1;
private final int O=-1;
/**
* Constructor for objects of class TTTBoard
*/
public TTTBoard()
{
// initialise instance variables
board = new int[3][3];
clear();
}
/**
* clear sets the board to the starting position
*
* */
public void clear()
{
for (int row=0; row<3; row++)
for (int col=0; col<3; col++)
board[row][col]=0;
}
/**
* get returns the contents of a board position
*
* @param row the row position
* @param col the column position
* @return a 1 for an X, -1 for O, zero otherwise
*/
public int get(int row, int col)
{
return board[row][col];
}
/**
* sets the contents of a board position to either 1 or -1
*
* @param row the row position
* @param col the column position
* @param value the choice (-1 for O, 1 for X)
* @return true if the choice was sucessfully made,
* false if that position has alread been taken
*/
public boolean set(int row, int col, int value )
{
if (board[row][col]==0)
{
board[row][col]=value;
return true;
} else
{
return false;
}
}
/**
* checks for Cats Game by looking for
* board loctions that have a "0"
*/
public boolean checkForCatsGame()
{
return false;
}
/**
* checks for an X win by looking for
* one of 8 ways that there are 3
* 1's in a row. For example:
* board[0][0]+board[0][1]+board[0][2]==3
*/
public boolean checkForXWin()
{
return false;
}
/**
* checks for an O win by looking for
* one of 8 ways that there are 3
* -1's in a row. For example:
* board[0][0]+board[0][1]+board[0][2]==-3
**/
public boolean checkForOWin()
{
return false;
}
/**
* a "String-Graphics" represention of the entire
* tic tac toe board
*
*/
public String showBoard()
{
String s;
s ="";
for (int row=0;row<3;row++)
{
for (int col=0;col<3;col++)
{
s+=" "+symbol(row,col);
if (col<2) s+=" |";
}
if (row<2) s+="\n---+---+---\n";
}
return s;
}
/**
* coverts the numerical contents of a board position
* to a String represention
* @param row the row position
* @param col the colum position
* @return an "X" "O" or a space
*/
public String symbol(int row, int col)
{
String s=" ";
if (board[row][col] > 0) return "X";
if (board[row][col] < 0) return "O";
return s;
}
}
import java.util.Scanner;
public class ConsoleTTT
{
// instance variables
public static TTTBoard b;
private static boolean xTurn;
private static int r,c,player;
private static final int X=1;
private static final int O=-1;
private static Scanner keyboard;
private static String message;
private static void init()
{
b=new TTTBoard();
xTurn=true;
keyboard=new Scanner(System.in);
}
private static int getChoice(String message)
{
String c;
int i;
do
{
System.out.print (message+": ");
c=keyboard.nextLine();
i=Integer.parseInt(c);
}
while (i<0 || i>2);
return i;
}
public static void main(String[] args )
{
init();
while (!b.checkForCatsGame() && !b.checkForXWin() && !b.checkForOWin())
// (I bet you can use De Morgan's Laws to change the above and
// yet get the same effect here!)
{
System.out.println(b.showBoard());
if (xTurn)
{
message="X's turn: ";
player=X;
}
else
{
message="O's turn: ";
player=O;
}
do
{
r=getChoice(message+"Choose row (0..2)");
c=getChoice(message+"Choose column (0..2)");
} while (!b.set(r,c,player));
xTurn=!xTurn; //change who's turn it is
}
// announce the outcome
if (b.checkForXWin()) System.out.println("X WINS");
if (b.checkForOWin()) System.out.println("O WINS");
if (b.checkForCatsGame()) System.out.println("TIE--CAT'S GAME");
}
}