I did the biweekly contest virtually last week, but today, I could no longer see my own answers or study other people's solutions, which sucked because I wanted to learn but it was locked for premium access.

So I want to know:

(1) For how long after the contest can I access the premuim problems?
(2) Are all biweekly contest problems premium?
(3) Are any of the weekly contest problems premium?

Thank you so much. Any help is appreciated.