Question

I’m trying to improve the speed of some code I’ve written. I was wondering how efficient accessing data from a 3d array of integers is?

I have an array

int cube[][][] = new int[10][10][10];

which I populate with values. I then access these values several thousand times.

I was wondering, seeing as all 3d arrays are theoretically stored in 1D arrays in memory, is there a way to turn my 3d array into a 1d one? For instance I could have cube[0] referring to the old cube[0][0][0] and cube [1] refering to the old cube[0][0][1].

I’m not sure how to go about doing it. I’m sure it’s possible but my brain is worn out.

Thanks

Answer 1

You can create the single-dimension array as follows:

int cube[] = new int[w * h * d];

And to access an element:

int value = cube[x * h * d + y * d + z];

But I doubt it will be much faster and you’re losing some convenience and safety. Before deciding to go through with this change it might be a good idea to perform some benchmark tests on your data to see if you actually have a problem and whether the change gives a sufficiently large improvement to be worth the extra complexity.