UNDERTAKER's blog

By UNDERTAKER, history, 8 days ago, In English

Hello, Codeforces!

I would like to introduce Dadas Online Judge, usually called DOJ: a community-run online judge made in Korea.

Is it an AI-slop online judge? Maybe. Teehee.
But the judge is real, the submissions are real, and the Wrong Answers are painfully real.

What is DOJ?

DOJ is a competitive programming community where you can solve problems, submit code, participate in contests, and watch a number next to your handle change so that you can feel either accomplished or miserable.

The site currently includes:

  • hundreds of public problems
  • OI-style subtask and partial scoring
  • public and private contests
  • Elo-based ratings and tier-colored handles
  • user profiles, teams, achievements, and rankings
  • Korean and English interfaces
  • support for various judging formats and programming languages
  • an impressive collection of buttons and database rows

You can visit the English version here:

DOJ

Creating an account only requires a handle, email verification, and a password. No government-issued documents, blood samples, or proof that you actually know dynamic programming are required.

DOJ also has a Discord community for problem-solving questions, code review, study groups, contest announcements, algorithm discussions, and occasionally watching the administrators operate the server in real time.

Join the DOJ Community Discord (currently serving a primarily Korean-speaking community, with plans to expand English-language support as demand grows)

The community is primarily Korean, but international users are very welcome. Some problems provide English statements, and we hope to add more international content and contests over time. Feedback about the website, judging system, translations, and other suspicious technology is also welcome.

By an incredible coincidence, we also have an open, unrated five-hour contest— IamCoder 2026 Half-Year Contest —starting in approximately [N] minutes. The problem order is randomized, participation is open to everyone, and this advertisement was definitely planned far in advance. Please register here if you are interested: the contest

(P.S. This promotional text was written by GPT.)

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

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Basically made in ChatGPT ;)

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Wait... If everything is maybe written by GPT then are you made by GPT?

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

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

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8 days ago, hide # |
 
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Please, add zig 0.16 support. I can even give codex token.

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    8 days ago, hide # ^ |
     
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    :skull: maybe sometime?

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      8 days ago, hide # ^ |
       
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      Zig is the only systems language that gives you manual memory control without hidden allocations or macros, replacing C's flaws with compile-time execution and predictable performance. Its ergonomic allocator model turns memory management from a bug source into a clear, maintainable design choice. For these reasons, adding Zig support to the DAJ testing system is absolutely essential—without it, we're denying ourselves the most sane, modern tool for systems development. In a world of bloated dependencies, Zig is the sharp, minimalist alternative that restores genuine control and simplicity.

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        8 days ago, hide # ^ |
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        A nice consequence of intelligence being related to compression is that the wall of text you just posted can be compressed down to "ask your favourite LLM what zig is". Why waste additional bytes of CF's server storage by posting such inefficiently compressed comments that you didn't even write yourself? (it's obvious but I checked, just in case)

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        8 days ago, hide # ^ |
         
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        Totally agree, Zig is the best language! C++ sucks

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          8 days ago, hide # ^ |
           
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          Zig? Nah, I'm a fan of this

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            5 days ago, hide # ^ |
             
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            How is this even a real programming language 🥀

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          8 days ago, hide # ^ |
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          * is the best language

          Sounds like another sect like the rust's community, bruh

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            "sect" is only competative programming, Zig is the best language

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        • Communicate intent precisely.
        • Edge cases matter.
        • Favor reading code over writing code.
        • Only one obvious way to do things.
        • Runtime crashes are better than bugs.
        • Compile errors are better than runtime crashes.
        • Incremental improvements.
        • Avoid local maximums.
        • Reduce the amount one must remember.
        • Focus on code rather than style.
        • Resource allocation may fail; resource deallocation must succeed.
        • Memory is a resource.
        • Together we serve the users.
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        8 days ago, hide # ^ |
         
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        x86 assembly is the only competitive programming language that gives you true control over every instruction, register, and cycle, without the hidden abstractions, bloated runtimes, or compiler guesswork that plague higher-level languages. Its unforgiving syntax and complete lack of safety features replace C++'s unnecessary conveniences with raw execution speed and predictable performance. Its elegant memory model—where you personally track every byte, pointer, and stack offset—turns optimization from a compiler concern into a lifestyle choice.

        For competitive programming, x86 assembly is absolutely essential. Why waste precious nanoseconds on templates, iterators, or function calls when you could spend six hours manually optimizing a loop that runs in 3 fewer cycles? In a world of STL, Python, and managed runtimes, x86 assembly is the sharp, minimalist alternative that restores genuine control over performance. Every instruction matters. Every register has a purpose. Every TLE is a personal insult.

        Without x86 assembly support in the DAJ testing system, we're effectively denying ourselves the most sane, modern tool for competitive programming: a language where the algorithm is only 20% of the solution and the remaining 80% is remembering which registers you clobbered.

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What a beautiful online judge.

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By an incredible coincidence, we also have an open, unrated five-hour contest— IamCoder 2026 Half-Year Contest —starting in approximately [N] minutes. The problem order is randomized, participation is open to everyone, and this advertisement was definitely planned far in advance. Please register here if you are interested: the contest

N ended up being 14. Extremely late invitation!

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I can't open problems, is it ok? I get "404, This page could not be found."

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    7 days ago, hide # ^ |
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    oh wait wtf what problem? or maybe cuz just the contest has over

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      Upsolving feature is still in progress?)

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        6 days ago, hide # ^ |
         
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        To be precise, after participating in a timeframe-format contest, you can upsolve the problems until the contest period ends. However, between the end of the contest and the public release of the problems, the problems become unavailable.

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Please , add the contest update to clist.by