[zeemonkee3]

How do I know that? What is the interviewer looking for?

Maybe in company A they are looking for developers who come up with a solution on their own and don't rely on external libraries or Google. Maybe company B don't like developers reinventing wheels and prefer they at least research prior art first.

I don't know what kind of culture your company has, but at the very least out of courtesy you can signal what the requirements are in your test.