Minesweeper in Java

Minesweeper is a video game where you are trying to clear a "board" while avoiding the hidden traps. There are individual squares which serve as these traps; all of the other squares are defined by the number of traps adjacent to that square. This means that a non-trap square can have a maximum value of eight (although this is highly unlikely). (Source). Here is an example of minesweeper wit a 2D GUI (Graphical User Interface): http://minesweeperonline.com/

This implementation utilizes 2D arrays but does not include a graphical user interface. For this java code, the "9" represents a trap or bomb while -1 represents a spot on the board which isn't visible. Therefore the original board looks like this:

This version also does not include any method to "flow" and reveal all zeroes adjacent to one another. Therefore, you need to reveal each square one at a time.

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public class MinesweeperGame { private int rows; private int columns; private int mines; private int board[][]; private int visibleBoard[][]; public MinesweeperGame(int inputRows, int inputColumns, int inputMines) { // Service Constructor rows = inputRows; columns = inputColumns; mines = inputMines; visibleBoard = new int[rows][columns]; board = this.createBoard(); board = populateBoard(board); visibleBoard(); } public int playerInteract(int inputRow, int inputColumn) { // Determines the result of an interaction with the board and changes all components appropriately if (board[inputRow][inputColumn] == 9) { return 2; } else { visibleBoard[inputRow][inputColumn] = board[inputRow][inputColumn]; } for (int i = 0; i< rows; i++) { // Checks for a win, if they haven't won yet, then they need to keep playing for (int j = 0; j < columns; j++) { if (board[i][j] != 9) { if (visibleBoard[i][j] == board[i][j]) { visibleBoard[i][j] = visibleBoard[i][j]; } else { return 0; } } } } return 1; } public void getVisibleBoard() { printBoard(visibleBoard); } // Calls the "visible" board, i.e. what the player can see public void getBoard() { printBoard(board); } // Calls the master board with all of the answers private int[][] createBoard(){ // Helper Method to instantiate the board int temp[][] = new int[rows][columns]; return temp; } private int[][] populateBoard(int inputBoard[][]) { // Helper Method to randomly place mines while (mines != 0) { int a = (int)(Math.random()*rows); int b = (int)(Math.random()*columns); if (inputBoard[a][b] == 0) { inputBoard[a][b] = 9; mines -= 1; } } for(int i = 0; i < rows; i++) { // This section then assigns each space of number based on the surrounding mines. for (int j = 0; j < columns; j++) { if (inputBoard[i][j] != 9) { int tempMines = 0; if ((j - 1) != -1) { if (inputBoard[i][j - 1] == 9) { tempMines += 1; } } if ((i - 1) != -1) { if (inputBoard[i - 1][j] == 9) { tempMines += 1; } } if ((i - 1) != -1 && (j - 1) != -1) { if (inputBoard[i - 1][j - 1] == 9) { tempMines += 1; } } if ((i - 1) != -1 && (j + 1) != columns) { if (inputBoard[i - 1][j + 1] == 9) { tempMines += 1; } } if ((i + 1) != rows) { if (inputBoard[i + 1][j] == 9) { tempMines += 1; } } if ((j + 1) != columns) { if (inputBoard[i][j + 1] == 9) { tempMines += 1; } } if ((i + 1) != rows && (j + 1) != columns) { if (inputBoard[i + 1][j + 1] == 9) { tempMines += 1; } } if ((i + 1) != rows && (j - 1) != -1) { if (inputBoard[i + 1][j - 1] == 9) { tempMines += 1; } } inputBoard[i][j] = tempMines; } } } return (inputBoard); } private void printBoard(int inputBoard[][]) { // Prints the board in a neat matrix fashion for (int i = 0; i < rows; i++) { for (int j = 0; j < columns; j++) { System.out.print(inputBoard[i][j] + " "); } System.out.println(); } } private void visibleBoard() { // Generates a blank "visible board" for (int i = 0; i < rows; i++) { for (int j = 0; j < columns; j++) { visibleBoard[i][j] = -1; } } printBoard(visibleBoard); } }

Here is the driver class for the above game. This version is very customizable; the user selects the # of traps and the dimensions of the board. Furthermore, this edition does not have an option to replay the game; it automatically shuts down after a win or loss.

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import java.util.Scanner; public class MinesweeperPlayer { public static void main(String[] args) { Scanner sc = new Scanner(System.in); System.out.println("Please enter three positive constants (the # of rows | the # of columns | the # of mines): "); int rows = sc.nextInt(); int columns = sc.nextInt(); int mines = sc.nextInt(); System.out.println("Please note that mines are represented by the # 9 while -1 refers to 'hidden' spaces"); System.out.println(""); MinesweeperGame game = new MinesweeperGame(rows, columns, mines); // Creates the game System.out.println(""); System.out.println("Let's get started!"); int x = 0; while (x != -1) { // Actually plays the game System.out.println(""); System.out.println("Please select a row | column to examine (zero-based indexing please): "); int inputRow = sc.nextInt(); int inputColumn = sc.nextInt(); int y = game.playerInteract(inputRow, inputColumn); // User input to select square if (y == 2) { // Response System: Win, Hit or Miss System.out.println(""); System.out.println("You have hit a mine!"); System.out.println(""); game.getBoard(); System.exit(0); // Exits after the game is complete } if (y == 1) { System.out.println(""); System.out.println("You won! Congratulations"); System.out.println(""); game.getBoard(); System.exit(0); // Exits after the game is complete } if (y == 0) { System.out.println(""); System.out.println("Here is the board for reference. Play you next move wisely."); System.out.println(""); game.getVisibleBoard(); // Continues if the game has not been completed. } } } }

Thank you to http://hilite.me/ for the source code formatting.

Github Code: https://github.com/MakeTheBrainHappy/Minesweeper