This was the second phone interview, the first being with a recruiter. I spoke with an engineer at Google and he asked me some general C++ questions (malloc, polymorphism, virtual functions, etc.). He then gave me a problem to write an algorithm for: finding the next number in a sequence.

The interviewer provided some hints along the way, but unfortunately, I was stuck for a good 10 minutes on one of his hints, which turned out to be a misunderstanding between us. I verbalized everything I was doing to try and make things as clear as possible. I didn't get the answer correct in the end.

He explained how to see where the sequence goes, but I don't understand how he would decide to use that approach. I feel like I would have no problem writing the algorithm, but I don't know how he arrived at the solution. It wasn't a very positive experience overall.

I don't expect to be asked for an in-person interview.

You have a sequence where each number is a multiple of 2 or 5 (so: 2^i * 5^j).

He gave the beginning of the sequence as 1, 2, 3, 4, 5, 8, 10, 16... and asked me to find an algorithm to calculate the next number in the sequence.