I'm working on my assignment which is to create a TicTacToe checker, and for some reason I'm unable to think of a way to do the first steps of creating the game. We read in from a text file that contains a line which represents one game; for example:
x,x,o, , ,x, ,o,o
That would look like this on a traditional board:
x|x|o
-----
| |x
-----
|o|o
Here's what I have so far:
class TicTacToe{
static String[][] game;
public TicTacToe(int size){
this.game = new String[size][size];
}
public static TicTacToe create(String input){
String tokens = input.split(",");
int size = (int)Math.sqrt(tokens.length); //For setting a size
// of the board
return null;
}
}
What I don't understand is how to return a new TicTacToe object: when I write my methods for checking rows, columns, etc. how will I get the board to check on? Am I going about this the right way?
[W]hen I write my methods for checking rows, columns, etc. how will I
get the board to check on?
The instance of your object should contain all of the information about the board. You have this (mostly) done already - game is the field which contains the information about the board. The only catch is that every board will contain the same board information, and if it's updated, it will contain the updated information.
If you want to treat this like a factory, then there are four things that you'll want to do:
Remove the static modifier from game. It's unnecessary and will lead to inconsistent states across multiple objects.
Make your constructor private - unless I'm missing something, there's no reason to initialize it outside of the factory.
private TicTacToe(int size) {
game = new String[size][size];
}
Or, better yet:
private TicTacToe(String[][] hydratedBoard) {
game = hydratedBoard;
}
I'll show you why in a moment.
Implement TicTacToe.create(String), and return the fully hydrated object. A suggestion would be to create the String[][] implicitly, create the object with that passed in as an argument to the constructor, and return your TicTacToe object.
public static TicTacToe create(String input) {
String[][] board = new String[3][3];
int i = 0; // count the row we're on
String[] tokens = input.split(",");
for(int j = 0; j < board.length; j++) {
if (j % 3 == 0) { // advanced to the end of the column set (SO)
i++;
}
board[i][j] = tokens[i*3 + j];
}
return new TicTacToe(board);
}
Provide some sort of getter to the board object. You might not have to do this per the assignment, but it's good practice. It could be either a straight-up getter on the String[][], or some sort of pretty-print representation; I don't know. I'll leave this implementation to the reader instead.
You're overthinking it. Rather than "return null;", use "return new TicTacToe(size);".
Although, usually when I create a static factory method (like your "create" method) I make the constructor private so it can only be called from the static create method.
...and then you will need to update the board if you want to actually remember the x/o positions you passed in...
Here I added an integration test for this game that might give you some ideas of how to create/think about the game.
public void testWinnerPlayerIWithVerticalLine() {
this.displayUnitTestDescription("Integration Test for having player 'X' as winner on a vertical line use case");
final IBoardGame<TicTacToeMove, TicTacToePlayer> ticTacTocGame = new TicTacToeGame();
final String playerIDisplayName = "X";
final String playerIIDisplayName = "O";
final TicTacToePlayer playerI = new TicTacToePlayer(playerIDisplayName);
final TicTacToePlayer playerII = new TicTacToePlayer(playerIIDisplayName);
ticTacTocGame.setGamePlayers(new TicTacToePlayer[]{playerI, playerII});
TicTacToePlayer[][] expectedBoardInteractionSnapshot = new TicTacToePlayer[][]{
new TicTacToePlayer[]{playerI, null, playerII},
new TicTacToePlayer[]{playerI, playerII, null},
new TicTacToePlayer[]{playerI, playerII, playerI}
};
ticTacTocGame.start();
ticTacTocGame.makeMove(new TicTacToeMove(0, 0));
ticTacTocGame.makeMove(new TicTacToeMove(1, 1));
ticTacTocGame.makeMove(new TicTacToeMove(2, 2));
ticTacTocGame.makeMove(new TicTacToeMove(0, 2));
ticTacTocGame.makeMove(new TicTacToeMove(2, 0));
ticTacTocGame.makeMove(new TicTacToeMove(2, 1));
ticTacTocGame.makeMove(new TicTacToeMove(1, 0));
this.displayBoardPlayerInteractionSnapshot(ticTacTocGame);
final TicTacToePlayer[][] actualBoardInteractionSnapshot = ticTacTocGame.getPlayerInteractionSnapshotBoard();
Assert.assertFalse(ticTacTocGame.isGameDraw());
Assert.assertTrue(ticTacTocGame.existWinner());
Assert.assertEquals(ticTacTocGame.getWinner().getDisplayName(), playerIDisplayName);
Assert.assertArrayEquals(actualBoardInteractionSnapshot, expectedBoardInteractionSnapshot);
}
If you are interested to find out more you can find the whole java implementation of the TicTacToe game: https://github.com/ncaralicea/tictactoe
Related
Hi I having been trying to program an algorithm using breadth-first-search that finds the shortest path for the blue dot to exit in the game. I am new to java and having trouble running/understanding the algorithm for the class. I have a class called gameModel which stores the statuses of each dot. The algoirthm is meant to test the fastest way the blue dot can exit the board without going through an orange dot (SELECTED) and if no way out than the player wins. I keep running the program and getting compile errors which i dont know how to fix. I included the controller class where the short dot was ran.
import java.util.Random;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.*;
/**
* The class <b>GameController</b> is the controller of the game. It implements
* the interface ActionListener to be called back when the player makes a move. It computes
* the next step of the game, and then updates model and view.
*/
public class GameController implements ActionListener {
private int size;
private GameModel gameModel;
private GameView gameView;
private boolean click;
/**
* Constructor used for initializing the controller. It creates the game's view
* and the game's model instances
*
* #param size
* the size of the board on which the game will be played
*/
public GameController(int size) {
this.size = size;
this.gameModel = new GameModel(size);
this.gameView = new GameView (gameModel, this);
click = false;
}
/**
* Starts the game
*/
public void start(){
if (click){
List start = new List {gameModel.getCurrentDot().getX(), gameModel.getCurrentDot().getY()};
List<int> targets = new ArrayList<>();
List<int> blocked = nwq ArrayList<>();
for (int i = 0; i < size; i++){
targets.add(i, 0);
targets.add(i, size);
targets.add(1, size);
targets.add(1, 0);
}
for (int i = 0; i < size; i++){
for (int j = 0; j < size; j++)
if(gameModel.getstatus(i, j) == SELECTED){
blocked.add(i, j);
}
String path = Breadth-First-Start(start, targets, blocked);
gameView = new GameView(gameModel, this);
gameView.getBoardView().update();
}
}
public Breadth-First-Start(start, targets, blocked){ // Need help with
Queue queue = new LinkedList();
queue.add(start + "");
while(!queue.isEmpty()){
String p = queue.remove();
if (p != blocked){ //If p is not in blocked paths
if (p == targets){ //If p is in targets
return "q + {p}";
} else {
queue.add("q + {p}");
blocked.add(p);
}
}
}
You method public Breadth-First-Start(start, targets, blocked) is declared wrong. You cant have - in method name, also you need to specify the return type (only constructors dont have a return type to be defined). Also you need to specify parameter types. From what I understand targets and start look like of type String and blocked looks like a List, please try replace the method head by the following public void breadthFirstSearch(String start, String targets, List blocked) not sure what return type you want as you dont have any returns in the method. But in your case you probably want the path so maybe of type List, or a boolean to know if there is a path or not.
What you're wanting to do has to do with graph theory. If two nodes are connected, an edge between them is created. In this case the orange dots would not be connected to anything as a path cannot exist through them. Dijkstra's algorithm is very useful for doing what you want, although it's breadth first instead of depth first. I'd recommend starting there, I'm sure there are examples of that algorithm being implemented in java.
The edges of the graph have weights which are compared in order to find the shortest path between two nodes.
I see that your blocked list declaration has nwq in it instead of new. That may be your issue right there.
Hope this helps
So I have numbered JLabels declared like so (In the class)
OP_1
OP_2
OP_3
etc..
And I have a number and a string.
What I want is that when, for example, the number is 2. I want to change the label text to the content of the string. This is part of a method that is supposed to take a string, put it into the last available JLabel, and then increment the number.
I am very confused, and help would be appreciated.
Here I created an array of JLabels and a method, updateNextLabel(String), which will update the next JLabel with whatever you enter for str.
public class Example {
static int count = 0; //Create a count
static JLabel[] array = new JLabel[3]; //Create an array to hold all three JLabels
public static void main(String[] args) {
//Set the default text for each JLabel
array[0] = new JLabel("This is OP1");
array[1] = new JLabel("This is OP2");
array[2] = new JLabel("This is OP3");
//Here is an example if you wanted to use a for-loop to update the JLabels
for (int x = 0; x < array.length; x++) {
updateNextLabel("This is the new text for OP" + (count + 1));
System.out.println(array[x].getText());
}
}
public static void updateNextLabel(String str) {
array[count].setText(str);
count++;
}
}
Instead of / additional to naming your labels by specific names you can later match them on, I'd think a Map of JLabels with Strings or Integers as keys might be a better approach:
Map<String,JLabel> labelMap = new HashMap<String,JLabel>();
labelMap.put("1", OP_1);
labelMap.put("2", OP_2);
This will allow later access of "The label for key 2" as well as "list me all that labels and find the one with text 2" as well
public class Game
{
private EnemyShip enemy1;
private EnemyShip enemy2;
private EnemyShip enemy3;
private PlayerShip player;
/**
* Initialises user's ship and guns
*/
public Game()
{
player = new PlayerShip();
enemy1 = new EnemyShip();
enemy2 = new EnemyShip();
enemy3 = new EnemyShip();
Can I make this enemy1,2,3 to be an array? I want to use enemy on a loop.
Or is there a way to make a loop for variable that is not an array? Like if I run the loop enemy1 will increment and become enemy2.
EnemyShip[] enemies = new EnemyShip[3];
for (int i=0; i<enemies.length; i++) { enemies[i] = new EnemyShip(); }
will give you an array of 3 EnemyShip objects. If the loop you're looking for is one that gives you a different instance variable each iteration then no you can't do that; you need to have them in a collection. However you can simplify the loop if you don't care about the index:
for (EnemyShip enemy : enemies) {
//do something with enemy object
}
As others have suggested, just do:
EnemyShip[] enemies = new EnemyShip[3];
for (int i = 0; i < enemies.length; i++) {
enemies[i] = new EnemyShip();
}
However, I think you should reconsider using an array. Using an array limits you to having, at maximum, as many enemies as will fit into the array.
Do you really know that you want at most 3 enemies at compile-time?
Why not make things more flexible and use a List instead? This will allow you to track as many enemies as you want to create at run-time. So for example, if the player is doing well you create more, if the player is doing poorly you create less.
List<Enemy> enemies = new ArrayList<Enemy>(3); // 3 is the expected capacity
for (int i = 0; i < 3; i++) {
createEnemy();
}
... elsewhere...
public void createEnemy() {
enemies.add(new EnemyShip());
}
Requirements change, particularly in game development. Try to avoid committing to things too early.
OK, I'm in the process of making a simple java swing chess game. This question is more about OOP design then Java Swing.
I have the following:
I have a Panel class that implements JPanel.
I then have an abstract class Piece that extends from my Panel class
Then I have my classes for the different Pieces: Pawn, King, Bishop etc that extend from my Pieces class
In my main ChessGame Class:
I am using an array of Panel to store the layout of my board
So the array will store, Panel objects, for board places with no pieces on it.
And it will store, the subclasses such as Pawn, Queen, Bishop etc (board places with pieces)
So, the top left square (0,0) maps to myArray[0][0]
My problem is that, to check if the place is empty or has chess pieces in it I have to use:
if(panels[x][y] instanceof Piece){
((Piece)panels[x][y]).makeMove();
}
What I'm asking is this terrible design? I know I should try and stay away from instanceof.
What would be a better approach?
Thanks.
You shouldn't combine the Model code (Piece) with the view code (JPanels). If you ever want to change how the board is displayed you have to change how pieces are stored!
A better design might be to separate Piece from JPanels. Then you can use a single JPanel to display a matrix of Pieces : Pieces[8][8].
My problem is that, to check if the place is empty or has chess pieces in it I have to use:
If you use a matrix, you can just have a null cell or use the Null Object Pattern to have an "empty" piece.
EDIT
Each cell in the piece matrix is a square in the board so piece[0][0] would be the top corner of the board (A8).
To paint the board your paintComponent() method would have to iterate over this matrix and draw each cell appropriately. There are several ways to implement this:
You would need to do a similar instanceof check to draw each type of piece differently
Make a new intermediate "paint strategy" object using the strategy pattern. This may require a matrix of strategy objects instead of piece objects. You may still need to do instance of checks, but maybe only the once to create the strategy objects.
After considering your problem, and knowing the problem domain, I would actually suggest the following...
In your class Panel implement a function int hasMass() as follows...
public int hasMass() {
return 0;
}
In your class Piece override that function as follows...
public int hasMass() {
if (isWhite()) // white pieces are negative.
return -1;
return 1; // black pieces positive.
}
Now you can check if the square has a piece, whether another given piece could take it... (because they have opposite polarity)... e.g. mass + mass == 0 means a capture, != 0 means the panel was empty. And of course an absolute value of 2 (for mass) would mean the move was illegal.
OK, ill start by throwing away the option of setting null to indicate that place is empty (you can do it ofc but using the Empty class is just 'better' in a way).
So let's say you have array of Panels representing your game board:
Panel[][] board;
Now for ilustration, how your class hierarchy could look like:
abstract class Panel extends JPanel { ... }
class Empty extends Panel { ... }
abstract class Piece extends Panel { ... }
class Pawn extends Piece { ... }
...
My Panel class is my Empty class is it not?
Not sure if i understand you, but let's have a look on what extends means exactly: in the show nmodel every Piece is also a Panel or every Pawn is also a Piece, so every Pawn can do all the same things as Piece (for example, 4 is complex number as well as natural number or real number, so in a way, you could say that real numbers extend complex numbers, since every real number is also a complex number)
So now you can have some nice abstract getTexture() method declared in Panel implemenented in Empty class and in all Piece subclasses, and when drawing a Panel, you dont need to look if it is empty or not.
Instead of creating (I assume) almost identical classes for each piece (Rook, Pawn, Queen etc.), you could just keep the original Piece class, make it non abstract and add a PieceType field to it. PieceType is just an enum that tells what type of piece (if any) is placed there. Instead of using instanceof, now you can check using panels[i][j].getType() == PieceType.ROOK. At least that's what I'm doing in my implementation :)
I'm also using JLabel instead of JPanel for my 8x8 board.
Instead of splitting panel to 8x8 smaller panels, you must draw the board and the pieces on a canvas. Later the players will eventually be dragging to move pieces on board. Also you could look for Bitboard presentation in chess game, although this presentation is only required for chess engines which are able to "think" for fast calculations, it is still useful when you have to check if the move that player is trying to make is correct.
Posible Bitboard:
public class BitBoard
{
public static final int P = 0;
public static final int N = 2;
public static final int B = 4;
public static final int R = 6;
public static final int Q = 8;
public static final int K = 10;
public static final int p = 1;
public static final int n = 3;
public static final int b = 5;
public static final int r = 7;
public static final int q = 9;
public static final int k = 11;
// empty field
public static final int empty = 12;
// number of pieces , squares
public static final int nPieces = 12;
public static final int nSquares = 64;
public static final int whitePieces = 12;
public static final int blackPieces = 13;
public static final int nBoards = 14;
public static long squareBits[];
// static member initialization
static
{
squareBits = new long[64];
long square = 1;
square = square << 8 * 8 - 1;
for (int i = 0; i < 64; i++) {
squareBits[i] = square >>> i;
}
}
long bitBoards[];
public BitBoard() {
bitBoards = new long[nBoards];
}
public boolean initBoard()
{
// Put the pieces on the board
EmptyBoard();
addPiece(0, r);
addPiece(1, n);
addPiece(2, b);
addPiece(3, q);
addPiece(4, k);
addPiece(5, b);
addPiece(6, n);
addPiece(7, r);
for (int i = 8; i < 16; i++) {
addPiece(i, p);
}
for (int i = 48; i < 56; i++) {
addPiece(i, P);
}
addPiece(56, R);
addPiece(57, N);
addPiece(58, B);
addPiece(59, Q);
addPiece(60, K);
addPiece(61, B);
addPiece(62, N);
addPiece(63, R);
return true;
}
public boolean addPiece(int whichSquare, int whichPiece)
{
bitBoards[whichPiece] |= squareBits[whichSquare];
bitBoards[nPieces + (whichPiece % 2)] |= squareBits[whichSquare];
return true;
}
private boolean removePiece(int whichSquare, int whichPiece)
{
bitBoards[whichPiece] ^= squareBits[whichSquare];
bitBoards[nPieces + (whichPiece % 2)] ^= squareBits[whichSquare];
return true;
}
private boolean EmptyBoard()
{
for (int i = 0; i < nBoards; i++)
{
bitBoards[i] = 0;
}
return true;
}
}
I would keep a structure of the pieces separate from the rendered board.
For example, I would make the chess pieces pure models w/o knowledge of hit they're rendered.
Pieces (baseclass)
+- Pawn
+- Knight
+- King
+- Queen
+- ..etc
This will allow you to keep an array of Pieces only, where empty squares are null.
For simplicity sake, I'd just have a matrix of peices:
Peices[][] board = new Pieces[8][8];
(of course an initialization method to traverse your 'board' and populate the board w/ the initial positions)
I would then have a visible board constructed of JPanels; a class called "Chess" to manage game; and the actual rendering of the tile/panel in the move function. Imagine:
// what a move might look like when initializing your panels
piece = board [0][0];
Chess.move(piece, 0 ,0); //responsible for clearing the old panel and rendering the panel at target location.
When the user interacts w/ your game..they click your panels..which will give you the panel coordinates. You use the same coordinates w/ your 'board' to determine what the piece is..how it can move etc..
Something like that...
I would just represent the game board using objects...for simplicity. Easiest to understand..and besides..computers are plenty fast now.
Good Evening. I am working on a program thats similar to the old game LiteBrite, where you place colored pegs on a panel and it lights up. In my program, it works similar in that when you click on the panel, it will create a new Ellipse (which ive named ColorEllipse that has specifications for location, size, and color) and that it will store it to be saved. Currently it is as an arraylist but i need it to be in a regular array. I am told the way that would be to make a new array, and copy all the contents of the old array into the new array. Now currently i use an arraylist, but unforutnately this program has specifications where we need to use a regular Array.
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.MouseEvent;
import java.lang.reflect.Array;
import java.util.ArrayList;
public class LiteBritePanel extends javax.swing.JPanel{
private final static int OFFSET = 5;
private static int LINE_WIDTH = 2;
private static int CELL_WIDTH = 25;
public ArrayList <Colorable> _circles; // where ColorEllipses will be stored
private ButtonPanel controlpanel; // used to set the color of peg that will be placed
public LiteBritePanel() {
this.setBackground(java.awt.Color.black);
_circles = new ArrayList<Colorable>();
controlpanel = new ButtonPanel(this);
this.addMouseListener(new MyMouseListener(this));
this.add(controlpanel);
}
public void paintComponent(java.awt.Graphics aPaintBrush) {
super.paintComponent(aPaintBrush);
java.awt.Graphics2D pen = (java.awt.Graphics2D) aPaintBrush;
java.awt.Color savedColor = pen.getColor();
pen.setColor(java.awt.Color.black);
for (int ball=0;ball<_circles.size();ball++)
if(_circles.get(ball).isEmpty())
return;
else
_circles.get(ball).fill(pen);
pen.setColor(savedColor);
this.repaint();
}
public void mouseClicked(java.awt.event.MouseEvent e){
boolean foundSquare = false;
for (int ball=0; ball < _circles.size() && !foundSquare; ball++){
if (_circles.get(ball).contains(e.getPoint()) == true){
foundSquare = true;
_circles.remove(ball);
this.repaint();
}
}
}
private class MyMouseListener extends java.awt.event.MouseAdapter {
private LiteBritePanel _this;
public MyMouseListener(LiteBritePanel apanel){
_this = apanel;
}
public void mouseClicked(java.awt.event.MouseEvent e){
_circles.add(new ColorEllipse(controlpanel.getColor(), e.getPoint().x - (e.getPoint().x%CELL_WIDTH), e.getPoint().y - (e.getPoint().y%CELL_WIDTH), CELL_WIDTH-3,_this));
_this.requestFocus();
boolean foundSquare = false;
for (int ball=0; ball < _circles.size() && !foundSquare; ball++){
if (_circles.get(ball).contains(e.getPoint()) == true){
foundSquare = true;
// code for removing ball if one is placed
_this.repaint();
}
}
}
}
}`
Now currently it is set as an Arraylist, but I need it to be in a regular array per this specification. then when the panel is clicked on, it adds a new ColorEllipse into that Array at that specific location (and repaints as necessary for it to show up). A later part of the program would be when i touch a peg thats already placed, it removes it, but thats for another time. right now I need to know how to increment sizes of the array and copy its contents into it. Would anyone be able to tell me what I should change?
To copy arrays, you could use the System.arraycopy(...) method (System API):
public static void arraycopy(
Object src,
int srcPos,
Object dest,
int destPos,
int length)
where you would first create a destination array, perhaps twice as big as the the source array, and pass the old array, the starting index (0), the new array, the destination starting index (0), the length (length of old array), and it should do the rest.
Also you don't want to call repaint inside of paintComponent, trust me. Use a Swing Timer instead. There's a good tutorial on this that Google can help you find.
Depending on how big your board is you can just create an array that has the same size as your board. Alternatively you can do as Hovercraft suggested but it all depends on whether you want to trade cpu for memory.
int MAX_POSSIBLE_ELEMENTS = ...
Colorable[] _circles = new Colorable[MAX_POSSIBLE_ELEMENTS];
....rest of code...
Notice that the maximum number depends on the height and width of the board so you should know this at compiletime.