Google Software Engineer interview questions

They contacted me quickly after submitting resume. One phone interview plus two trips out. First trip had 5 hour-long interviews with engineers. Second trip had two. All involved coding problems. Hard interview process, but fair. My only real complaint is I had to fly out two times. Better if I could've done it in one trip, perhaps a two day interview.

I was asked some C++ questions (malloc/polymorphism/virtual functions/etc) and then gave me a problem to write an algorithm for (find the next in a sequence of numbers). The interviewer gave me some hints along the way, but unfortunately I was stuck for a good 10 minutes on one of his hints that turned out to be a misunderstanding between us. I verbalized everything I was doing along the way to try to make things as clear as possible. I didn't get the answer correct in the end. He told me 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.