I'm pretty confident I would've been able to come up to the solution in better circumstances, maybe even without hints. But it was clear in this case that the

I'm pretty confident I would've been able to come up to the solution in better circumstances, maybe even without hints. But it was clear in this case that the interviewer just took a question from the company's bank of questions and was alt-tabbed for half the interview, I have felt the energy early and I was also half-checked out. I'm aware I'm saying this post factum, but I had a very fun first interview with that company and matched well with the first interviewer so my expectations were high, and then I got hit by the big tech style interview when it was an early stage startup.