I agree that the functional paradigm works very well for a problem like Hanoi. In fact, it's certainly very good for any type of operational/algorithmic challen

I agree that the functional paradigm works very well for a problem like Hanoi. In fact, it's certainly very good for any type of operational/algorithmic challenge. However, the question isn't just alluding to functional questions or algorithms. It's talking about designing a solution that can be used to manage multiple types of operations in a well organized manner. Think: I want to change the colors of the tower pieces. I want to analyze them based on their properties. I want to attach meta information to them as I sort them. Perhaps I want to keep track of where they go over the course of their journey to the tower. Maybe I'm a particularly indecisive architect that wants to build 5 types of towers. As you may imagine, it's possible to do this well in FP and in OOP. But the most likely best solution is a healthy mixture of both, to handle the true nature of problems that have verbs AND nouns.