Meta Software Developer interview questions

One campus interview then a onsite. The onsite had 3 interviews 30 mins each, all technical. There were no behavioral questions and the interviewers were pleasant. The process was through my university.

It's from my career fair on campus. The HR asked about my android project then give me a question related to how to select a user's potential known friend from the users friend's friend list. Finally I asked three questions about my position. The coding question should be two or three usually. I think I failed because I didn't explain what I was thinking during the coding process