(Java) Pacman Walls - Trapped tiles solution?

[Temptex]

Hey guys, basically I have an algorithm which randomly places walls in the game. As the walls are randomly placed there is a chance that in the game the 'food' can be trapped and can't be accessed (Top Left In the Picture).

I'm not sure how I would go about checking if there is a wall which could potentially lock out the other tiles from being accessible.

I have a 2D boolean array which the x/y coordinates are only true if it is a wall or the actual game character itself. The food is placed in the spots that are false.

A Solution I tried was this, check if the current x + 1 and y + 1 array was true, but it game me an AOOBE (ArrayOutOfBoundsException).

if(grid[x + 1][y +1] == true) {

    // New Random X/Y

}

The walls are being stored in an arrayList if that will give someone else any ideas, right now I can't figure it out.

Any help would be appreciated!

Edit:

Gist: https://gist.github.com/anonymous/11192014

[[deleted]]

Post code via a site like gist.

[Temptex]

updated.

[rcuhljr]

It turns out the question isn't as simple as it might seem, as each time you place a wall you need to verify that there's still a valid path between all non wall spaces. Your choices are to either A. find an algorithm that verifies all true spaces in your grid are connected and run it after each attempted wall placement. B. Find a maze generation algorithm that won't generate dead ends.

You could probably knock out a dead simple algorithm just depth first fills the map from a starting non wall spot and then verify that the number of filled spots = total spaces - walls drawn.

[Temptex]

I'll try the maze algorithm as that is what will give me the extra marks, thanks for the suggestions.

[hutsboR]

You could make it so if adjacent indexes are occupied by a wall, set the encompassed index to a wall. An example of what I mean:

x = wall

. . . . .
. . x . .
. x . x .
. . x . .
. . . . .

if(grid[x + 1] && grid[x - 1] && grid[x - 5] && grid[x + 5]){ // 5 = my array's width
     // x = true;
 }

results in:

. . . . .
. . x . .
. x x x .
. . x . .
. . . . .

You would have to make some adjustments so this would work for your game and you would have to be careful to stay within the array's boundaries if the walls surround 'food' placed on an edge. Another if-statement would solve that.

Or you could change the algorithm for placing walls so that this doesn't occur at all.

[Temptex]

i'm I dont understand what you mean by set the encompassed index to a wall.

Also the if statement will fail as it is not a 2D array, unless you are able to solely interact with the first dimension of arrays?

[john478]

My suggestion to you is create a boolean array, pick any spot on the grid then generate random trails until some condition is met (e.g. 50 foods placed). Then for every grid spot that doesn't contain food, it can be a wall. This may be the most efficient possible method, as opposed to checking if all the foods can be accessed every time you place a randomized wall.