Question

I’m currently working on a 15 puzzle game for Android for school. Sadly I’ve ran into a problem.

I need to rewrite this equation to get a row and column from it instead of a index. Have a look at the code and se if you guys can help me out!

This takes a row and column and return me a corresponding index.

int index = 4 * (row - 1) + (column - 1);

However, now I would like to turn a index into a row and column.
So does anyone know how to sort of reverse this equation to return a row and a column into two different ints.

Thank,
Mikael

Answer 1

Try this:

row = index / 4 + 1;
column = (index % 4) + 1;

Note that this (and the original formula) only works if column < 5 (which it is, of course, for a 15 puzzle).