If problem A itself is very hard then many participants will not even participant in the contest because of fear of loosing rating.
And because of that number of participants is too less than than the number of participants registered for the contest.
And it will affect the overall rating of many users. (Obviously who atleast solved A should have higher ranking than the one who not even solved A , but according to current scheme if user not made any submission that means user is no more participant for that contest.)
Make problem A very easy so that they do atleast one submission for the contest.
What's your thought on this point ?
Thank you.