I applied online and had a 45-minute phone interview. They asked me to fill out a questionnaire that consisted of scale-of-1-to-10 expertise questions for programming languages, areas of computer science, and so on.

The phone interviewer asked me two questions, and for the first, I had to code on paper and read it out.

I received an email the following week inviting me to Kirkland for an on-site interview. Google reimburses all of your expenses during the on-site interview trip. Be sure to retain all receipts and send scanned copies within 15 days of your on-site interview.

I am playing a card game called 24. Cards ace to king are numbered 1 to 13. During a given round, I am provided with four cards to play with from the shuffled pack. If the numbers from the four cards result in 24, then I win the round if I shout '24' first. How would you code a function for this?

A quad tree is used to represent a black/white image. If you are provided with two such image representations, write a function to create a third tree that represents the merged image. (Black overrides white; mixed overrides white.)