Question

I’m drawing a HUGE blank here.

Everything I’ve found is about getting an index from a given row and column, but how do I get a row and a column from an index?

The row is easy: (int)(index / width).

My brain is suffering massive bleed trying to compute the column.

Shame on me.

Answer 1

For a zero-based index, the two operations are, where width is the width of the structure:

row    = index / width
column = index % width

Those are for C using integers, where the division rounds down and the % modulo operator gives the remainder. If you’re not using C, you may have to translate to the equivalent operations.

If you don’t have a modulo operator, you can use:

row    = index / width
column = index - (row * width)