Bloomberg interview questions

I took an online test which was pretty easy and then I took the phone interview. I had a friend who had taken the phone interview a few weeks before me and the questions they asked him were pretty easy. They asked me pretty basic questions in the beginning and then asked me a difficult question. They asked me, what is the best way to find the duplicates within two intersecting linked list. The answer I gave was very inefficient so they gave me hints but I was really nervous and I wasn't able to figure it out. I havent heard from them yet so I doubt I will get accepted for the in-house interview.

1. phone interview (within 48 hr from applying): questions about recent economic news, resume, why bloomberg, S.T.A.R. 2. on the following day: in-house interview with a team leader and one employee, interviewers were mainly interested in Excel/PowerPoint skills