Groupon Software Engineer interview questions

Begin with a phone interview. Then there is a final round on-site interview with 4 Software Engineers in Groupon. When I start the on-site interview, I found that the interviewer seemed that they don't want do this on-site interview. Sometimes I talked my solution on the board. But they looked at the other part of the room and lost at some other thing they were thinking about.

I got the interview through college career fair. Two engineers interviewed me. The first 20 minutes were resume questions. Then there were two algorithm questions.