I had a phone screen with an engineer. He asked the same LeetCode hard question that appears on many DoorDash threads, but he changed it slightly, requiring a trick to solve.

I solved it right away, even before he introduced the edge case. The interviewer was not very helpful and kept giving vague hints, such as "just look on line 12."

Eventually, we ran out of time. The interviewer offered to show me the solution. He modified my code, claiming it was the solution, but it did not pass the test cases either, and he seemed confused.

I got to ask some questions. He mentioned they use Kotlin, so I stated I was not interested in working with Kotlin. I probably did not pass the interview anyway.

Count the differences between trees.