I'm trying to help you. When I say PAE is out of bounds - accept it and try a new avenue. Don't spend time defending it as a choice.

Your interviewer has specific things he wants to see.

This is no different than asking you to reverse a string, watching you allocate space for a new one, and then me refocusing to say "OK - but the string is ginormous and there is no more memory available - now what will you do". Because I want to see the in-place solution.

You said you want to be a programmer. I'm happy to help you achieve that and coach you through what passes as interviewing these days. The really-hard-puzzle-solve-this-on-the-spot interview is very popular now.