Creating sets of similar elements in a 2D array

Question

I am trying to solve a problem that is based on a 2D array. This array contains different kinds of elements (from a total of 3 possible kinds). Lets assume the kind as X, Y,

Answer 1

You may want to check out region growing algorithms, which are used for image segmentation. These algorithms start from a seed pixel and grow a contiguous region where all the pixels in the region have some property.

In your case adjacent 'pixels' are in the same image segment if they have the same label (ie, kind of element X, Y or Z)