Is it possible to create new test cases for practice problem.

I fully understand that it might happen that there is not worst case test case for all algorithms solving the problem. Also I’m not a fan of changing the test cases during the contest. But I think that I’s good idea to maintain test cases in practice room to be as good as possible.

Few examples:

Is it possible to create test case and rejudge all submissions for some problem in practice room?

I can imagine more difficult process: specifying also the solution I’d like to challenge and if it is correct challenge, then all submissions will be rejudged.


Yes. But this involve getting the test data verified by the problem setter which may not even be possible for the old problems.

Please send us the test data to and we shall try and get them added to the problem and rejudge all the submissions.


perfect, thanks for your answer

In fact, there are several technical complications. The solutions from the actual contests can not be rejudged in any way or it may ruin results of the contest and sometimes even top may change. So in rejudge tool we should carefully set limits for submissions IDs that should be rejudged. And it could be very dangerous since mistyping just one digit could touch solutions from the contests. Of course we can revert test sequence back and rejudge again but in any case it is quite unpleasant procedure.


The rejudge will only happen on the practice section and not for the contests. The test data can only be added to the problems in the practice section.