Homework 6: Minesweeper

The goals of this assignment are:

• Design and implement programs containing multiple functions
• Apply top-down design principles to building a larger program
• Work with files, loops, conditionals, and variables

Requirements:

• Every method you created should be tested in the class’s main method.
• Every java file should have a header. However, DO NOT PUT YOUR NAME IN YOUR HEADERS. On gradescope we grade your assignments anonymously so including your name in your Java file will defeat that purpose. However, please include your name in your README.txt
• Every method should contain a javdoc that briefly describes the method, lists the params, and the return type/value. Use the notation that we used in lectures.

WARNING: In this assignment you are NOT ALLOWED to import any packages or classes besides for java.util.Scanner, java.io.File, and java.io.FileNotFoundException. For example, you cannot use the builtin Arrays java class to print out an array. Doing so will result in earning ZERO POINTS for a method that uses it.

IF YOUR CODE DOES NOT COMPILE, YOUR SUBMISSION WILL BE DEDUCTED ATLEAST 10%.

Minesweeper

In minesweeper, players try to uncover each cell of a NxM grid without hitting any bombs. N represents the number of rows in the grid and M represents the number of columns.

When the game starts, the program will generate a board and show it to the user with all cells hidden. When the user selects a cell, the game will reveal the contents of the cell. If the cell has bombs in any of the 8 adjacent cells, the cell will show a count of the number of neighboring bombs. If no bombs are adjacent, the cell is empty. If the cell contains a bomb, the game is over. If the user uncovers all cells, the user wins!

We will build up our programs in two parts.

1. Board

Write a program, Board.java, that generates and displays a NxM minesweeper board. The user should specify the following parameter as command line arguments.

• a name of a file that contains a board.

Update: 03/13 (8:23PM): board1.txt, board2.txt, board3.txt, and board4.txt are all examples boards that we provide. We will test your program with other boards. For example, we might have a file name called test.txt that looks like

- - -
X - -

You can assume that the board files will be in the same directory as Board.java and Minesweeper.java.

$ javac Board.java
$ java Board board3.txt
0 0 2 X 3 2 X 1
0 0 2 X X 2 2 2
0 1 2 3 3 2 2 X
0 1 X 1 1 X 2 1
0 1 1 1 1 1 1 0

$ java Board board4.txt
X X X X X X X 3
X X X X X X X X
X X 8 X X X X X
X X X X X X 7 X
X X X X X 4 X X

Requirements:

• You must use command-line arguments to read in the name of the file that contains the board.
• You should use a 2D array to store the board. We recommend using a 2D array of integers, where each cell contains the count of neighboring bombs. If the cell contains a bomb, you can use a special value, such as -1, to denote it.
• Update (02/13 5:45pm): If no filename is passed in as a command line argument, the program should print a message to the user saying so and then terminate
• Update (02/13 5:45pm): If a filename is passed in as a command line argument and the file does not exist, the program should print a message to the user saying so and then terminate.

We recommend that you organize your code to use functions for generating and displaying the board. You will re-use these functions in the next question.

We have provided method stubs in Board.java for you to complete.

2. Minesweeper

Write a program, Minesweeper.java, that implements the game of minesweeper. Re-use your code from the previous question. You should also write a method to validate user input.

Below are several examples showing how the game should play:

• User wins
• User loses

Your output doesn’t need to look exactly the same but it should be clean and easy to read.

Your program should use command line arguments to determine the file name that contains the board!

Update (02/13 5:45pm): If no filename is passed in as a command line argument, the program should print a message to the user saying so and then terminate. If a filename is passed in as a command line argument and the file does not exist, the program should print a message to the user saying so and then terminate.

We have released 4 example boards: board1, board2, board3, board4

Main Method

Your main() method should use the methods below to do the bulk of the work.
The general outline of the program is as follows:

• Print out a welcome message. You can do this in main, or define a function for it.
• Set up initial variables before entering the game loop. You will need at least two boards: one with the generated bombs and one that keeps track of which cells the user has uncovered already.
• Set up your game loop (hint: use a while loop). Each time through the loop, the program will ask for a cell to uncover and update the board.
• Print the output of the game. If the user selects a cell with the bomb, they lose. If the user uncovers all non-bomb cells, they win.

Design

Think about how to subdivide the features of the game into methods. Each method should implement a single, well-defined task. For example, do not put your entire game loop into a single method! Use methods to help abstract sub-tasks, for example,

• to validate input
• to check whether the user has uncovered all non-bomb cells
• to display the current state of the board
• printing text with banners

NOTE: You can define a 2D array of booleans to keep track of which cells the user has selected already.

3. Extra Credit

Implement your own unique minesweeper game in MyMinesweeper.java. Be sure to point out to us your original ideas and features in your readme. Below are ideas

• If the user selects an empty square, uncover all adjacent cells until you reach a non-empty cells.
• Be able to work with a non-rectangular board.

README.txt

In a text file called README.txt answer the following questions:

1. How much time did you spend on the homework
2. What did you learn from this homework
3. optional: What did you struggle with during this homework
4. optional: any other feedback you would like to share

Dont forget: make sure to fill in the header in all of your java files.

Submitting

Submit the following files to the assignment called HW06 on Gradescope:

1. Board.java
2. Minesweeper.java
3. MyMinesweeper.java
4. README.txt

Make sure to name these files exactly what we specify here and name the methods exactly what we specify too. Otherwise, our autograders might not work and we might have to take points off.