I think you're wrong about the 100% bad place to work just because someone asked you to reverse a string without using library functions.
I would think your computer science education would have prepared you to plan out such an algorithm. Sadly, its pretty had for a place to confirm you have subconscious skills by asking a question and then waiting for you to come back the next day with the answer once it popped into your head.
First off, I'm self taught, I don't have any computer science education. Secondly, it wouldn't be too hard to give me an actual problem that the company is actually having, and letting me think about it for a few days, then come back with my solution. Why must all interview problems be made up?
I would think your computer science education would have prepared you to plan out such an algorithm. Sadly, its pretty had for a place to confirm you have subconscious skills by asking a question and then waiting for you to come back the next day with the answer once it popped into your head.