As brought up by this comment, there were 6 hacks during the contest but they were not added to the main tests for the submissions during the contest. They are added only for practice submissions (roughly 3 minutes after system testing ended).

Having 6 hacks highly suggests weak pretests, and it is likely that at least a few hundreds of solutions will fail when they are judged with these tests. This could significantly change the scoreboard, and should not be neglected.

We are not late. Error_Yuan, please rollback the rating update and rejudge the solutions.