Fast way of iterate over trues in boolean array

Question

I have a big array of booleans and i need just to work with the true elements, and need theyer index.

for (int x = 0; x < cells.length; x++) {
        for (int y = 0; y < cells[0].length; y++) {

                if (cells[x][y]) {
                    g.fillRect(x * cellSize, y * cellSize, cellSize, cellSize);
                }

        }
    }

so how can i do that without the two foor loops and save the time?

Answer 1

I'd say this is the best you can get.

You are already using a primitive array and I expect primitive boolean type.

The only thing I could suggest is saving cells.length and cells[0].length in final variables before the loops, it could save some time, but the compiler may already optimize this on its own.