Phone screening for software research. It mostly consisted of background questions with one technical question.

I was asked to create a function to check if a binary tree is sorted. I used a recursive solution that, at first, failed in some cases.

The interviewer pointed out that there was a bug. I found the problem and devised a different solution. My second solution was correct, but the interviewer disagreed.

I told her I couldn't find the bug she was referring to and that I'd email her with a correction as soon as I did. After some research and consideration, it turned out I was correct, so it was a weird process overall.

I didn't get an offer.

I was asked to create a function to check if a binary tree is sorted.