RetailMeNot Software Engineer Intern interview questions

First interviewed on campus, and was asked some easy problems about OO, and a simple problem about detecting duplicate items in an array. Invited to Austin to get the on-site interview. I was not prepared well so I didn't perform well in the process. But the problems are not that tough. If you have some basic ideas on linked list, hashmap, tree,etc, I think you can handle that. Also, they focus on web development so they might prefer people who knows python and php.