They were very professional. They sent me a lot of emails on how to prepare for your interview at Facebook.

They also held internet live sessions with current developers where you could ask questions about the process and about potential interview questions.

First, they conducted a phone interview where they asked a coding question, and you had about 40 minutes to answer.

There was only one thing I was unhappy about. In the live session before the phone interview, they said the most important thing was to solve the problem they asked you, and only then try to improve your code. Well, in my interview, I solved the problem in only 30 minutes but wasn't able to improve the code efficiency in the last 10 minutes. A day later, they sent me an email saying it wasn't good enough.

Well, what can you do? It's Facebook.

You have a list of people, and a function that returns true/false if one person knows the second person.

Write a function that finds a VIP, which everybody knows and he doesn't know anybody else.