MikeMirzayanov's blog

By MikeMirzayanov, 2 weeks ago, translation, In English,

Hello!

As an allowed language on Codeforces and Polygon C++17 has been added. The compiler we use is 32-bit mingw64 version 7.2.0 (later will be updated when new versions are released). We are using a patch from halyavin to speed up I/O when using scanf/printf (for more details, read here). The exact used distribution can be installed on Windows from our package manager called PBOX using the link http://pbox.me/packages/mingw-w64-7

The exact compilation command line is:

g++.exe -static -DONLINE_JUDGE -Wl,--stack=268435456 -O2 -std=c++17 -o %name%.exe %1 2>compilation.log

Wish you successful solutions in C++17,
MikeMirzayanov

 
 
 
 
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2 weeks ago, # |
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MikeMirzayanov Can you please add any music player to CF? I want switch Hurts' and "Time and Glass"' songs without switching to another tab or phone.

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    2 weeks ago, # ^ |
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    Also a porn collection, please. Could help with hard problems (ahem).

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2 weeks ago, # |
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MikeMirzayanov today I faced a problem when I want to add problem from polygon to mashup contest, I can add an old problems but when I want to add a new problem the error Could not download problem descriptor is shown up, and I am create the package and add access read for codeforces in polygon. what is the problem?

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    2 weeks ago, # ^ |
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    Are you sure you have provided an access to the problem for "codeforces" user?

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      2 weeks ago, # ^ |
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      Yes

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        2 weeks ago, # ^ |
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        I need more details. Please, send me a message with ids of the problem in Polygon and your mashup id. Thanks.

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          2 weeks ago, # ^ |
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          Fixed now. Thanks.

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            2 weeks ago, # ^ |
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            Thank you the problem solved

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              2 weeks ago, # ^ |
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              but now its give judgment faild when i submit code to the problems in codeforces

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                2 weeks ago, # ^ |
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                I am having the same problem. The problems i create always fail to judge submissions.

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2 weeks ago, # |
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Looks like all my submissions will be in C++17 from now on. Although C++11 was overkill for my skill

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2 weeks ago, # |
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Hope that user can use gif as the profile photo!

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2 weeks ago, # |
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Why not a 64-bit compiler?

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2 weeks ago, # |
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C++17 is way too old, waiting for C++20 support

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2 weeks ago, # |
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Is C++17 support __int128 ?

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    2 weeks ago, # ^ |
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    It's not in standard and never was. It's an extension for 64-bit compiler (very fast 2-"digit" biginteger), so it won't be on Codeforces unless it begins to use 64-bit compiler. Reasons not to do this are described in this comment.

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2 weeks ago, # |
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I always wonder why CF is based on 32-bit compiler. Does server run on 32bit cpu?

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    2 weeks ago, # ^ |
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    No, it's so because of Kernel Patch Protection on 64-bit editions of Windows.

    As you know, Codeforces servers run machine code from untrusted sources. If you want to do this without compromising system security, you need to establish a sandboxed environment. There are many different ways to achieve this, the most obvious one is virtualization. But it's really expensive to restart a virtual machine each time when a new test is run. So, here comes another method of sandboxing: system call interception. By using it, you can intercept dangerous system calls, such as ExitWindowsEx or OpenFile and terminate the running solution due to security violation. This is done by loading a kernel-mode driver and patching the system call table. But KPP prevents this. That's why 32-bit versions of Windows are used for implementing such sandboxes.

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      2 weeks ago, # ^ |
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      Why not sandbox on Linux? You will have your 64-bit compiler while being able to isolate executables from using system calls.

      Is there a reason Linux is not used?

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        2 weeks ago, # ^ |
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        Is there a reason Linux is not used?

        Visual Studio compiler.

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      13 days ago, # ^ |
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      Do you know kernel patch protection alternative for linux?

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2 weeks ago, # |
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Looks like christmas came early this year!!!!

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13 days ago, # |
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Are there any new features that are useful for compeititons as well?

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12 days ago, # |
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I am not getting any download link on the given page. Please help.