Don't worry about it. Hard advice I know, but google is just as desperate as everyone else for quality candidates. Get some sleep, drink some coffee before your interview, and just talk through the problems as you get to them. If this is your first interview it's likely a phone interview. They usually last about an hour, and they just want to make sure you can think through a problem.<p>Also, regardless of whether it works or not, don't let it affect you. I know some really brilliant people who couldn't get into google, but are masterful coders.
I went through a technical interview with Google a few months ago (the first stage phone screening).<p>The best tip I can give you is to expect some relatively basic CompSci questions, but ones that might catch you off guard if you're not from a CompSci background. Examples being things like finding a value in an ordered list when you don't have direct access to the data set (just a method call to get one item by its index), and don't know how big it is.<p>Try not to go for the easiest answer (like incrementally pulling every item in the dataset until you get the one you want) first, try to solve the problem the "right way" - even if it takes a bit longer.<p>Other than that, relax - Interviews are for both the employer and the candidate, it's not an interrogation.<p>Good luck! :D
Regardless of how talented you are, the coding interview is flawed. That is, even if you are great, if you mess up an interview you likely won't get the job. This isn't to discourage though, just know that if you don't get in it DOES NOT mean that you aren't talented. It means you had a bad day and you should try again soon.
Eat breakfast and be calm and collected. Don't stress.<p>Check out Steve Yegge's blog post about interviews if you haven't already:
<a href="http://steve-yegge.blogspot.com.au/2008/03/get-that-job-at-google.html" rel="nofollow">http://steve-yegge.blogspot.com.au/2008/03/get-that-job-at-g...</a>
Even though it is a technical interview, confidence is always key. Visualize yourself succeeding and believe in yourself. I would stick to your guns and just do what you know best.<p>"Go confidently in the direction of your dreams. Live the life you've imagined."
― Henry David Thoreau
Say what you're thinking, so they can follow your thought process. Most interviewers won't fault you for giving a suboptimal or even incorrect solution, as long as you recognize it and continue working towards a better solution.
Consider starting a start-up if you are at all interested in executing on your own ideas. If you are able to get a job at Google, you should be able to execute on a good idea. 20% time is a minuscule investment in your ideas for a company that is investing $300 million in start-ups.