I like this OOP guy

Easy to understand solution using OOP patterns. However I think if there would be thousands/millions of operations this code would cause significant perfomance issues because of object creation.

Good for getting used to takling problems with distributing responsibilities to each method

I would like to see your solution using a generic interface for data types implementing algebraic rings.

Using the good concepts on small problems might seem bloated, but is good training for good solutions for big problems.

Yes, there are much shorter solutions, but your solution is much more Java.

exactly 😉

It looks to me like they were intentionally using this as an opportunity to work on design patterns

he's actually talking about this: KISS... x)

don't speak like that with others. yours also can be even simpler.

keep it simple stupid

wtf???)

I love this solution because it is more objective

This is a nice use of the Command pattern.

This is very nice, long but explicit and clear