There is something new for you. It seems that now it will be easier to reuse problems from the archive for educational and other purposes.
As you know, problems from past Codeforces rounds can be added to mashups simply by their codes of the form like
1234D (contest ID + problem letter). I myself regularly used this when I taught at Saratov University — it was very convenient to prepare trainings: problems have expected complexity and topics, there are Russian and English statements, you can see the analysis and many solutions. Because of hacks and uphacks, problems in the archive usually have strong tests. Almost all of them are well-prepared. In addition, with the help of user lists, you can easily pick up problems for a group of students that they did not solve.
But there was also an issue: the problems in such trainings were easily googled. And if the majority of adult participants could cope with the temptation to spy on the solution or tests, then beginners sometimes acted dishonestly. I received several requests to come up with something with this flaw. One of the most recent such requests was from Daniel Darooha Sleator (https://en.wikipedia.org/wiki/Daniel_Sleator). Thanks, Danny!
So the work seems to be complete. Meet a new feature on Codeforces: now you can rewrite statements for problems in mashups, completely replacing it with your own. More details about the capabilities of the new functionality:
- a new icon-link appears in the problem list in mashups, by clicking on which there will be a form for creating/editing a new statement;
- you can use the original text of the statement as a template when writing your own: be very careful — you must exactly repeat all the details of a statement so that problems do not formally differ;
- this form compares the set of formulas in the original text and the new statement, and if they differ as sets, there will be a corresponding detailed warning;
- you can specify your own tests from a statement (examples) — here you also need to be very careful so that they are formally correct;
- if you added examples, then solutions will be judged on them first, and only after on official tests;
- you can upload your own image files and use them in statements;
- there is a setting to temporarily disable the use of the new statement (for example, if it is still under development).
Considering that there are already more than 6500 problems in the archive, an excellent perspective opens up for organizing trainings and educational sessions.
I hope this innovation will be useful. Write in the comments what can be improved and/or corrected.