I am happy to tell you that Codeforces will soon free you from reading those endless "Please, give me test #??" in the comments. Now you can click on a link with the submission-id on the status page and it will show not only the original solution texts, but also the tests on which testing was performed (the judging system report). It will not contain the full inputs/outputs/answers if they are too large – you will have to wait for now and enjoy their prefixes. As soon as we understand that there're no bugs in the implementation, we will open all the previous contests to view the tests.
However, that is only the first step; later you will be able to download contest problem archives that will contain full texts (or their generators) as well as the authors' solutions and other materials.
Of course we do not want Codeforces problems to be copied from one "online judge" to another one. You’ve got to understand that Codeforces puts huge effort into preparing tasks and organizing contests. That's why we limit the material usage to make using our problems on websites or in other automatic testing systems impossible. On the other hand, we will be glad if the contest materials will be useful for individual training or for some assemblies, training sessions etc. with the onsite participants. Read the license text carefully as we want some Codeforces data to be published near (or inside) the problem tasks.
At the moment it is version 0.1 of the license, we will perhaps change a lot in it, but I guess the idea will undergo no changes.
Codeforces materials usage license (v. 0.1)
- You may publish the texts of Codeforces problems in any open sources, but you must preserve a direct link to the site http://codeforces.ru (http://codeforces.com for English statements) and indicate Codeforces as the problem source. These data should be located in the close proximity to the statement, be easily noticeable and readable. It is forbidden to publish Codeforces problems in open sources supporting automatic testing (such as online judges or similar resources).
- You must not use tests and other materials of the problems (generators, checkers, validators) to publish tasks in open sources supporting automatic testing (such as online judges or similar resources) even provided the original problem conditions has been changed.
- You may use the provided material: tests, generators, checkers, validators and others for individual training or to organize short-term teaching and training activities with the participants present on-site. Task conditions should contain the data from paragraph 1 of this license. The secondary (subsequent) distribution of the tasks should contain this license and comply fully with the license’s rules.
Uh, what if I want the whole test case, and not just the "prefix".
May I publish translated texts of Codeforces problems?
Yes, but you follow the rules 1-3.
Can authors use their own problems and tasks in 'their own' 'open sources supporting automatic testing'?
Also if well-known problems are proposed in CF rounds, can one use that problem? it somehow seems coinciding with term 2
I want to use my problems in my online judge. Is it possible? It seems that my curiosity coincides with this comment.
I'm not sure that the question is so strange and funny. Maybe, IIIIIIIVVVIVIIVIIIIXX wanted to ask, is Codeforces' rights for the problems exclusive, or shared with original problems' authors.
In other words: "My friend is an author of some problems of some CodeForces Rounds. And he wants to know, is it legally to use some of theses problems for another round at another platform."
Nevertheless, original IIIIIIIVVVIVIIVIIIIXX's question is not clear enough.
It's been nine years and we still don't get the full test case ...?
MikeMirzayanov I wonder if it would also be okay to share codes of some problems as open source but while linking them to the original source from CodeForces?
MikeMirzayanov I wonder if I could use the test for academic research purpose only, including publishing papers. Thanks!
May I know what is your research problem statement?
"Little Vasya found array in left pocket, queries in right pocket. Each query is of form ..."
Can i publish my solution & explanation of codeforces problems(mind this that not the editorial of codeforces copied and pasted but my explanation), with the codeforces problem link attached at the beginning and make this as paid material so that whoever buys this material will have access to my simpler explanations of the codeforces problems or this violates any rules?
You can do it.
Thank you Sir!
MikeMirzayanov please confirm whether this license is up-to-date (since the post is 11 years old and the last comment is almost 2 years old) and we are still allowed to use links to codeforces problems on other websites while giving full credit to codeforces and if all solving/submitting is done codeforces. Are we still allowed to use links to problems if the website's code is not public and we require people to sign up (but anyone may sign up for free)? Just making sure that I clearly understand what "open sources" refers to here.
Yes, you can. This license is actual but subject to change in the future.
MikeMirzayanov Is it allowed to use the problem statements on my website with clear visible links to the Codeforces Problem and submission page?