Amazon Intern Software Developer interview questions

I initially got contacted for a full time but then requested an interview for an internship as i graduate in 2015. I had two 45 minute phone interview, pretty standard questions, Given a log of users visit to a site for a day, how would you find returning users given the log visit for another day. I can't remember other questions but they all focused on knowing how to use data structures, runtime and design. I got and acceptance letter two weeks later.