I’m having an unusual issue with the problem MNMXROT. I solved this problem for full credit in the contest in which it appeared. More recently, however, I’ve been helping one of my students work through the problem, and it appears that a mysterious extra test case has appeared. Here is the last submission to this problem before my student’s first attempt–note that there are eleven test cases. Here is my resubmission of the same code–note that it now receives WA and that a twelfth test case has been added.
I’ve resubmitted several other AC solutions, including my AC solution from in-contest and my implementations of several other approaches, and all receive WA on test twelve (see my submission history at this link). As a result, I’m curious whether anyone has code that still ACs this problem with the new test case. Additionally, if anyone has a copy of the test case and would be willing to upload it, I’d appreciate if you could post a link. I don’t want to jump to the conclusion that the new test data is incorrect, but it’s certainly concerning that so many solutions fail only this test case, as it implies that either the new data is incorrect or that the data was extremely weak in-contest.