with t as (
select submission_date,
       h.hacker_id,
       name,
       count( submission_id) as br, 
       dense_rank() over (partition by h.hacker_id order by submission_date) as rbr,
       dense_rank() over (partition by submission_date order by count(*) desc,h.hacker_id ) as rk1   
from hackers h inner join submissions s on h.hacker_id=s.hacker_id
group by submission_date,h.hacker_id,name
    ),
tt as (
select t.*,
       dense_rank() over (partition by submission_date order by br desc,hacker_id ) as rk,
       count( hacker_id) over (partition by submission_date) as broj 
from t where rbr=datediff(day,'2016-03-01',submission_date)+1
        )
select t.submission_date,tt.broj,t.hacker_id,t.name from t inner join tt on t.submission_date=tt.submission_date
where tt.rk=1 and t.rk1=1
order by 1