kuviman's blog

Codeforces Updates (April-May, 2015)
By kuviman, history, 9 years ago, translation, In English

Hello!

Codeforces never sleeps, and I am going to tell you about our recent updates which weren't announced yet.

Testlib

  • testlib moved to GitHub, and the version 0.9.9 with C++11 support has been released.

Polygon

  • Added basic support for test groups. Now you can specify group for each test, run invocations by test groups, and you can view summary for each group on the invocation page. If group is specified for a test, it will be added to the problem descriptor (i. e. <test cmd="gen 1 2" group="testGroup" method="generated"/>).
  • You can now view problem statements and validator for a problem/contest on the same page. This makes finding mistakes in translations and in validator much easier (before you had to open them on separate tabs and switch between them, which is not comfortable). On the problem statements page the "Review" link has been added:

    On the contest page the corresponding link appears in the sidebar:

Codeforces

  • Missing an announcement during contest is now even harder — messages additionally are showed using Notification API.
  • Fixed a bug in API: in contest.hacks method defender and hacker were confused.
  • Fixed a bug about status filter reset. This was happening sometimes when request went to another Codeforces server.
  • Fixed a bug about local storage overflow. If you had a problem with local storage overflow, you had to run localStorage.clear(); in browser console. Now Codeforces uses local storage more carefully.
  • Syntax is now highlighted when you are hacking:
  • Invisible characters are now shown when you view a submission. Before it was confusing why you get WA:
Before Now
  • You don't have to upload images to a third-party site anymore, you can do it while editing a topic. Right under the topic content you can select one or more images, for each of them there will be a link generated which you can use to insert it into the text:
  • Improved topic categorization, for example soon you will not have to search for Codeforces important materials (documentation, rules, etc.) in blogs, they will be structured and available on a special page.
  • Implemented a feature to add rights to edit the topic to a list of users. For now this opportunity will be available for reputable users, who will be able to edit topics with documentation, tutorials and similar materials themselves.
  • Improved testing for determinism of generators: we remind you that generators have to be written so that they produce the same input each time, this is tested more reliably now. Do not initialize random number generators with current time!
  • Implemented a feature to view revision history for a topic. History may be available either to all users or only to the editors. By default new topics will have history available to everyone. If you enable viewing history, then you will be able to publish auto comment when you have edited the topic, which will have links to the previous version, new version and the link to compare them.
  • Now users which didn't take part in rated events for more than 6 months are hidden in the ratings pages. Also they do not affect a country/city/organization ratings.

And this is not all! Expect more improvements soon, for example we work on rating inflation problem and lots of other things.

  • Vote: I like it
  • +505
  • Vote: I do not like it

Comments Comments (18)
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9 years ago, # |
  Vote: I like it +14 Vote: I do not like it

I tried hacking today and it took much longer time than usual loading the codes.

I don't know it is because of the updated view of the codes or my connection was slower than usual.

But anyway I think you should give the option for the user to activate or de-activate this feature.

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9 years ago, # |
  Vote: I like it +38 Vote: I do not like it

Wow, that is super!

Especially "Fixed a bug about local storage overflow.", "Syntax is now highlighted when you are hacking", "Improved topic categorization," and "we work on rating inflation problem" are changes which should be easily noticeable to everyone :).

I'm happy to hear that issues I brought to daylight like http://mirror.codeforces.com/blog/entry/17872 and earlier http://mirror.codeforces.com/blog/entry/15787 are improved :).

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9 years ago, # |
← Rev. 2   Vote: I like it +5 Vote: I do not like it

How about adding Rust programming language? 1.0 was released like three weeks ago :)

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    9 years ago, # ^ |
      Vote: I like it +8 Vote: I do not like it

    according to MikeMirzayanov Rust will appear "in time". Also, I personally see no benefits of using it in competitive programming instead of c++. There are lots of annoying things. Non-indexable strings, non-intuitive container interfaces, endless error handling, mess with IO, and of course its famous memory model.

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      9 years ago, # ^ |
      ← Rev. 2   Vote: I like it +3 Vote: I do not like it

      Competitive programming is fun. Rust is fun too.

      At least for me, that is the reason :)

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        9 years ago, # ^ |
          Vote: I like it +3 Vote: I do not like it

        Conclusion: competitive programming with Rust is double fun.

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      9 years ago, # ^ |
        Vote: I like it +6 Vote: I do not like it

      There are X languages with big faults!

      Let's make one that avoids them!

      later...

      There are X+1 languages with big faults!

      Classic.

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9 years ago, # |
  Vote: I like it +17 Vote: I do not like it

"Syntax is now highlighted when you are hacking"

Awesome!!

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9 years ago, # |
  Vote: I like it 0 Vote: I do not like it

I know for a fact that when you are submiting and your program fails on the sample test, that would not count as a fail attempt.

Can you make it so you can see the example testcases when you submit you code during the contest? For ex. I wasted ~20 minutes yesterday because i was printing with cerr, and yes, it failed on the first example (the one in the problem) but i didn't knew why.

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    9 years ago, # ^ |
      Vote: I like it -6 Vote: I do not like it

    And offtopic: I don't know why, but G++11 4.9.2 on CF doesn't recognise std::to_string .. even after i included string.

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    9 years ago, # ^ |
      Vote: I like it +9 Vote: I do not like it

    You can always use 'custom invocation' tab during the contest.

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9 years ago, # |
  Vote: I like it +19 Vote: I do not like it

Does hacking still need Flash to be installed?

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9 years ago, # |
  Vote: I like it 0 Vote: I do not like it

CodeForces is nice. and it's going to become better than nice ;)

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9 years ago, # |
  Vote: I like it 0 Vote: I do not like it

The "link to comment" (which looks like #) heads to "http://mirror.codeforces.com/blog/entry/(BLOG_ID)?#comment_(COMMENT_ID)", so whenever I click it, it reloads the whole page, as the link is different from the current one ("http://mirror.codeforces.com/blog/entry/(BLOG_ID)") Could you please fix this?

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9 years ago, # |
  Vote: I like it +13 Vote: I do not like it

Auto comment: topic has been updated by MikeMirzayanov (previous revision, new revision, compare).

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