Not the company for you, obviously. What you described sounds like amateur hour on their part, and here's why: if you ask a question which has a single sought

Not the company for you, obviously. What you described sounds like amateur hour on their part, and here's why: if you ask a question which has a single sought after answer, it doesn't give you any data except the binary did they solve it or not. What you want are coding challenges whose answer tells you about that person and how they compare in thinking to others, so there must be a range of valid solutions.