I had a similar experience. This past Fall, I was interviewing with multiple companies, and I received questions that were very similar.... some being the same exact thing. I was nice, however, and told them out front that I had seen the problem before and asked for another.

I don't regret doing that; some may have passed the interview by keeping quiet even though they had seen the problem, but those people won't go far in the world because they cheat. They will eventually get called out for it and lose their reputation.