[adrianratnapala]

This is why I like the question. As an interviewer, I will leave that matter open and see if the candidate asks for clarification. If so, bonus! But I will tell them to just solve for ASCII.

The worst-case scenario is a "self-hazing" where someone sees the encoding difficulties and freezes up instead of asking for clarification. I've never seen that happen though, in my experience though, everyone -- even the good ones -- just assume ASCII.

And I am happy enough if they do it correctly.