ikashukov

with participants as (
    select distinct(user_id) as user_id, name as user_name
    from submissions
             left join problems p on submissions.problem_id = p.id
             left join users on users.id = submissions.user_id
    where p.contest_id = (select max(id) from contests)
), problemcount as (
    select user_id, count(distinct (problem_id)) as problem_count
from users
         left join submissions on users.id = submissions.user_id