Automine

Screenshots
Automine wins easily on beginner.


Automine wins most of the time on intermediate.


Automine rarely wins on expert.

How Automine Interacts with Windows Mindesweeper
Windows Minesweeper doesn't have an interface that a program can use to directly interact with it, so Automine must do this just as you or I would play minesweeper. Automine looks at the screen to determine the current board position and it moves and clicks the mouse to indicate its next move.

Luckily, Java provides a class that makes all this easy to do. The Robot class provides methods that let a program move the mouse, click the mouse, and take screenshots.

When Automine starts, it must determine the position of the minesweeper board on the screen. It does this by taking a screenshot and then searching the screen in a checkerboard fashion for a group of pixels that looks like a minesweeper tile. Once it has found a match, it then looks at neighboring pixels to determine the size of the board. When Automine needs to rescan the board, it knows the position and size of the board already and it simply looks at each tile to determine what type of tile it is. In all, Automine needs to be able to distinguish between the 12 different kinds of tiles shown below. You can notice that it is possible to do this just by looking at a few carefully selected pixels per tile.



Since Automine looks at screenshots to determine the position of the minesweeper board on the screen, it can become confused if you have things that looks like minesweeper boards on the screen (such as images of minesweeper boards). Automine expects that the board does not move on the screen, so it can also become confused if the board does get moved.

How Automine Plays Mindesweeper
The algorithm that Automine uses to play minesweeper is very simple. In pseudocode it looks like this:

while the board is not solved and a mine has not exploded
    // Try to flag as many tiles possible with 100% certainty.
    for each tile in the board that is marked with a number
        count the number of neighboring tiles that are blank
        count the number of neighboring tiles that are flagged
        if the number of blank + flagged neighbors equals the number marking this tile then
            flag each neighboring tile that is blank
        endif
    endfor

    // Try to click a tile with 100% certainty.
    for each tile in the board that is marked with a number
        count the number of neighboring tiles that are blank
        count the number of neighboring tiles that are flagged
        if the number of flagged neighbors equals the number marking this tile and
            the number of blank neighbors is greater than 0 then
            click each neighboring tile that is blank
            break out of the for loop
        endif
    endfor

    if no tile was clicked then
        select a random tile and click it
    endif

    update the board position by taking a screenshot
endwhile

The algorithm basically flags as many tiles as it can with 100% certainty, then clicks on a tile with 100% certainty or if this is not possible it clicks randomly, then updates the board and repeats until the board is solved or a mine explodes.

Here is an example of when automine can flag the blank tiles with 100% certainty.


Here is an example of when automine can click the blank tiles with 100% certainty.


Of course, it is possible to have Automine win more games with a more complicated algorithm, but this will have to wait until a later version.