Referred by an employee, I received a letter setting up a phone interview almost immediately.

The interviewer had an accent and was a little hard to understand, but he was very nice throughout the interview.

Anyway, the interviewer was nice, and the questions were simple if you thought about them simply. Since this was my first interview and I am not a CS student, it is fair that I failed it, but it was still a little disappointing.

The interview included two questions, both focused on basic programming.

1. Revert the bit sequence of a 32-bit number. For example, 0100 0110 0000 0001 should become 1000 0000 0110 0010. The interviewer specifically requested the most efficient programming method.

2. Facebook friend network connection. This question was a bit confusing. Suppose you have a Facebook API that allows you to access all of a person's friends. Can you determine if person B is connected to person A through the friend network? For instance, if A has friends (C, D, E), and C has friends (B, G), then A is connected to B.

I initially approached the second question with a 7-layer for loop, aiming to avoid overloading memory with excessive data. However, the interviewer did not seem to appreciate this approach. I also struggled with a follow-up question about the big O notation of my code. When asked for the big O, considering a map search as N (nodes) + V (edges), I incorrectly answered N. I was unaware of the correct complexity.