> But as long as I kept to the letter of the rules, I considered myself ethically in the clear.

Yeah, totally, just to be clear I'm not judging.

In fact, if you programmed it to handle those operations, one could argue you had already learned a big chunk of what was going to be measured in the exams.

Kind of similar to the paradox of creating and using cheat sheets, is highly likely you're accidentally learning about the subject matter in the process of writing the sheet, sometimes up to a point where the cheat sheet is not necessary anymore.