I think it really depends on your philosophy. Elixir doesn't have many idioms or strong suggestions as to how to go about a problem, so you see different approaches. For some, code being easy to reason about is more important than efficiency. I personally adhere to two things above efficiency:

• datastructures should carry the majority of the complexity; algorithms should be clean.
• No optimization before practical bottlenecks are identified at the expense of clarity.

Other than that, I really appreciate this different take on the solution!

Edit: I also like that this solution directly solves the problem and only the problem. Very nice.