FifteenPuzzle Game :: SourceCode

I'm posting the code of a game that I wrote recently. Game name is FifteenPuzzle or N-Puzzle.

You can download the file here.

File Name: FifteenPuzzle.java

import java.awt.*; import java.awt.event.*; import javax.swing.*; import java.util.ArrayList; import java.util.Arrays; import java.util.Collections; /** * It is a sliding puzzle that consists of a grid of numbered squares * with one square missing, and the labels on the squares jumbled up * * <p> The <code><b>n-puzzle</b></code> is known in various versions, * including the <code></b>8 puzzle, the 15 puzzle</code></b>, and with * various names. If the grid is <b>3×3</b>, the puzzle is called the * <code><b>8-puzzle </b></code> or <code><b>9-puzzle</b></code>. If * the grid is <b>4×4</b>, the puzzle is called the <code><b>15-puzzle * </b></code> or <code><b> 16-puzzle </b></code>. The goal of the * puzzle is to unjumble the squares by only making moves which slide * squares into the empty space, in turn revealing another empty space * in the position of the moved piece.</p> */ /** * * @author Anil Madamala * Copyright (c) 2007,2008 Anil Madamala * Any problems contact: amadamala+code@gmail.com * */ public class FifteenPuzzle implements ActionListener { /* Dimention of the Board */ private static final int DIM = 4; // For N * N board DIM = N /* Total number of cells in the board */ final int SIZE = DIM * DIM; /* Win state */ final String[] WIN = new String[SIZE-1]; /* Initial Height of the board*/ private static final int HEIGHT = 400; /* Initial Width of the board*/ private static final int WIDTH = 400; /* Initial empty cell in the board*/ private int emptyCell = DIM * DIM; /* 15 puzzle Board, of size (4 X 4)*/ private JButton[][] board = new JButton[DIM][DIM]; private JFrame frame; private JPanel panel = new JPanel(); // Suppresses default constructor, ensuring non-instantiability. public FifteenPuzzle() { if(DIM <= 1){ JOptionPane.showMessageDialog(null, "You Win The Game."); System.err.println("Dimention Should be greater than 1 to play"); System.exit(0); } // Initialize the win state for (int i = 1; i < SIZE; i++) { WIN[i-1] = Integer.toString(i); } System.out.println("Win State:" + Arrays.asList(WIN) ); } public static void main(String[] args) { FifteenPuzzle game = new FifteenPuzzle(); game.initializeBoard(); /* Initializes the 15-puzzle game board */ } /** * Gives index value corresponding to [row,col] of a square * @param i, row * @param j, column * @return the index of the corresponding to the row and column */ private int getIndex(int i, int j) { return ((i * DIM) + j); // i * 4 + j } /** * Generates the random intitial state for the game. * Assigns unique random number to each square */ private void initializeBoard() { ArrayList<Integer> intialList = new ArrayList<Integer>(SIZE); // Repeat until creation of solvable initial board for (boolean isSolvable = false; isSolvable == false;) { // create ordered list intialList = new ArrayList<Integer>(SIZE); for (int i = 0; i < SIZE; i++) { intialList.add(i, i); } // Shuffle the list Collections.shuffle(intialList); // Check list can be solvable or not isSolvable = isSolvable(intialList); } System.out.println("Initial Board state:" + intialList); // Assigns unique random number to each square for (int index = 0; index < SIZE; index++) { final int ROW = index / DIM; // row number from index final int COL = index % DIM; // column number from index board[ROW][COL] = new JButton(String.valueOf(intialList.get(index))); // intializes the empty square and hide it if (intialList.get(index) == 0) { emptyCell = index; board[ROW][COL].setVisible(false); } // Decorating each square board[ROW][COL].setCursor(Cursor.getPredefinedCursor(Cursor.HAND_CURSOR)); board[ROW][COL].setBackground(Color.BLACK); board[ROW][COL].setForeground(Color.GREEN); board[ROW][COL].addActionListener(this); panel.add(board[ROW][COL]); } // Initializes the Frame frame = new JFrame("Shuffle Game"); frame.setLocation(400, 200); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); frame.pack(); frame.setSize(HEIGHT, WIDTH); // Initializes the panel panel.setLayout(new GridLayout(DIM, DIM)); panel.setBackground(Color.GRAY); // Initializes the content pane java.awt.Container content = frame.getContentPane(); content.add(panel, BorderLayout.CENTER); content.setBackground(Color.GRAY); frame.setVisible(true); } /** * Verifies the board for solvability. * For more detals of solvability goto URL: * http://mathworld.wolfram.com/15Puzzle.html * @param initialList * @return true, if the initial board can be solvable * false, if the initial board can't be solvable */ private boolean isSolvable(ArrayList<Integer> list) { int inversionSum = 0; // If this sum is even it is solvable for (int i = 0; i < list.size(); i++) { // For empty square add row number to inversionSum if (list.get(i) == 0) { inversionSum += ((i / DIM) + 1); //add Row number continue; } int count = 0; for (int j = i + 1; j < list.size(); j++) { // No need need to count for empty square if (list.get(j) == 0) { continue; } else if (list.get(i) > list.get(j)) { // If any element greater count++; // than seed increse the } // inversionSum } inversionSum += count; } // if inversionSum is even return true, otherwise false return ((inversionSum & 1) == 0) ? true : false; } /** * If any button in the board is pressed, it will perform the * required actions associated with the button. Actions like * checking isAdjacent(), swapping using swapWithEmpty() and also * checks to see whether the game is finished or not. * * @param event, event performed by the player * @throws IllegalArgumentException, if the <tt>index = -1 </tt> */ public void actionPerformed(ActionEvent event) throws IllegalArgumentException { JButton buttonPressed = (JButton) event.getSource(); int index = indexOf(buttonPressed.getText()); if (index == -1) { throw (new IllegalArgumentException("Index should be between 0-15")); } int row = index / DIM; int column = index % DIM; // If pressed button in same row or same column makeMove(row, column); // If the game is finished, "You Win the Game" dialog will appear if (isFinished()) { JOptionPane.showMessageDialog(null, "You Win The Game."); } } /** * Gives the index by processing the text on sqare * @param cellNum, number on the button * @return the index of the button */ private int indexOf(String cellNum) { for (int ROW = 0; ROW < board.length; ROW++) { for (int COL = 0; COL < board[ROW].length; COL++) { if (board[ROW][COL].getText().equals(cellNum)) { return (getIndex(ROW, COL)); } } } return -1; // Wrong input returns -1 } /** * Checks the row or column with empty square * @return true, if we pressed the button in same row or column * as empty square * false, otherwise */ private boolean makeMove(int row, int col) { final int emptyRow = emptyCell / DIM; // Empty cell row number final int emptyCol = emptyCell % DIM; // Empty cell column number int rowDiff = emptyRow - row; int colDiff = emptyCol - col; boolean isInRow = (row == emptyRow); boolean isInCol = (col == emptyCol); boolean isNotDiagonal = (isInRow || isInCol); if (isNotDiagonal) { int diff = Math.abs(colDiff); // -ve diff, move row left if (colDiff < 0 & isInRow) { for (int i = 0; i < diff; i++) { board[emptyRow][emptyCol + i].setText( board[emptyRow][emptyCol + (i + 1)].getText()); } } // + ve Diff, move row right else if (colDiff > 0 & isInRow) { for (int i = 0; i < diff; i++) { board[emptyRow][emptyCol - i].setText( board[emptyRow][emptyCol - (i + 1)].getText()); } } diff = Math.abs(rowDiff); // -ve diff, move column up if (rowDiff < 0 & isInCol) { for (int i = 0; i < diff; i++) { board[emptyRow + i][emptyCol].setText( board[emptyRow + (i + 1)][emptyCol].getText()); } } // + ve Diff, move column down else if (rowDiff > 0 & isInCol) { for (int i = 0; i < diff; i++) { board[emptyRow - i][emptyCol].setText( board[emptyRow - (i + 1)][emptyCol].getText()); } } // Swap the empty square with the given square board[emptyRow][emptyCol].setVisible(true); board[row][col].setText(Integer.toString(0)); board[row][col].setVisible(false); emptyCell = getIndex(row, col); } return true; } /** * Checks whehere game is finished or not * @return true, if the board is in final state * false, if the board is not in final state */ private boolean isFinished() { // Check 1-15 elements whether they are in right position or not for (int index = WIN.length - 1; index >= 0; index--) { String number = board[index / DIM][index % DIM].getText(); if (!number.equals(WIN[index])) { return false; // If any of the index is not aligned } } return true; } }

Comments and suggestions will be great.



           -Anil Madamala