You're exactly right wrt interviewing. I was talking in general and not in the context of an interview.
If you are interviewing someone and they solve the problem you ask, and then you don't give them some sort of guidance or constraints to meet your "correct" guidelines, then you aren't doing a good and fair interview.
If you are interviewing someone and they solve the problem you ask, and then you don't give them some sort of guidance or constraints to meet your "correct" guidelines, then you aren't doing a good and fair interview.