On the contrary, it shows that the OP has a very good understanding of the type system. Plus, it’s an understandable approach given the code golf nature in which the original problem was presented. (Line length and character limits screams “code golf” to me)
I give lots of interviews and I try very hard to resolve ambiguity in the expectations and requirements. Up front I explain what the purpose of the interview is and what I intend to evaluate. It’s silly to assume everyone is equally able to read between the lines and coding interviews are already a very poor approximation of what a day to day software engineering job looks like, so I try my best to set expectations up front.