Very nice write up! Concise and to the point. I've never had a whiteboard interview before and honestly, I don't know if I could do it. I understand why big name companies do it, but it just feels weird as a requirement. My first interview out of college consisted of them having me explain inheritance in Java and what an abstract class was. It was quite underwhelming for all the studying I had done.
Thanks! I have mixed opinions on whiteboard interviews; it's definitely a controversial topic. From Google's perspective, I believe they see it as one way to be as fair as possible. I won't argue the merits, though. All I can say is I knew what to expect coming in, and prepared for it. There were no surprises, and that's definitely a good thing.