Hello everyone, have you ever faced a situation where you get a non-AC verdict on a certain testcase, but you are unable to debug your solution because you can't analyze (or view) that large testcase? or you are pretty close to the the solution, but don't want to look at the editorial yet, and wished you had more (small) testcases to brainstorm on paper? or a situation in which you feel you could've debugged your solution better if you could just run them on the hack-testcases (which are usually placed at the end of the testset)?
I've created cfdebug.org to help you in the above situations. It's a tool through which you can see all the small/corner testcases of any problem on Codeforces. By defult, it's sorted by input size (so that it's easier to dry run on paper), but if you get WA on, say TC19, you can filter it to remove all smaller testcases with index less than 19. This way, you'll have access to the next smallest testcase for you to debug. You can also copy the input/output to test the program seamlessly on your local environment.
Let me know your feedback/suggestions/feature-requests in the comments. (I was thinking of making a Chrome Extension that detects whether you are on a CF problem page, and opens the corresponding page on CF Debug via some keyboard shortcut. Would that be helpful or is it an overkill?).
The code isn't public at the moment, but if you have something in mind that you'd like to collaborate on (or if you just want to know how I built it from scratch), you can drop me an email at email@example.com