The interviewer was very rude and was not interested in taking the interview. He asked me one programming question. I explained the logic and approach to tackling that program. He said yes and asked me to write the code. I took around 15 minutes to write the code on white paper and after that, he did not check the code and told me that the approach is wrong and stopped the interview. I had attempted the interviews with Amazon & Google before and was unable to crack those interviews as well. But I was happy by the way that the company treats the candidates.

Binary tree.