The interviewer was very bad at defining the problem statement and couldn't give me good test cases. I didn't have a good understanding of the problem going into it. They was also not helpful when I asked clarifying questions. With all this, I made a mistake initially and instead of letting me figure out what's happening, they proceeded to dictate his solution to me. They seemed impatient in the sense that he wanted me to already "know" the answer before I had the time to think about it. They also jumped in several times in the middle of me debugging instead of letting me figure the bug out.
I think this has been the worst interview experience I've ever had. As someone who's been an interviewer, what I'm looking for in candidates is to see their line of thinking when approaching a problem. Candidates often make mistakes and seeing how they identify and fix their mistakes is also something that I would be looking at. To me, it seemed like the interviewer today was only interested in knowing whether I've already solved this problem on leetcode.