Submissions

I submitted(problem Hiring) some times the same code, the first 4 times my program passed only some test, but by the fifth submission my program passed all tests.

There is problem with grader ...

Just submit same code 2 times in row, and 2nd one is good submission ...
Grader is taking submission before current one to grade, so if you submit 2 in row and hope no one submitted between your 2 submission, grader will grade your first submission :D

Hope admin will solve this problem soon ...