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NOJ JudgeServer

JudgeServer for NOJ, inspired by QDUOJ.

Compiled Images

This package is available on Docker Hub and Github Container Registry.

You can download from Docker Hub:

docker pull njuptaaa/judge_server

Since v0.3.0 all version are pre-released on Github Container Registry then upload to Docker Hub later, thus you can download latest version from GHCR:

docker pull ghcr.io/njuptaaa/judge_server

You might want to specify a certain version of JudgeServer, for example, if you are using NOJ v0.18.0, you need at least JudgeServer v0.3.1 for SPJ supporting libraries and Node.js compiler to function properly:

docker pull njuptaaa/judge_server:v0.3.1

You can download latest experimental build by using nightly tag, they are latest for sure, but may contain developing features that your NOJ version does not currently support:

docker pull njuptaaa/judge_server:nightly

Compile Yourself

You can compile NOJ JudgeServer yourself.

docker build . -t njuptaaa/judge_server

If you are using networks that have limited internet access, you can try using proxy to build. In the following example we using a proxy located on port 1080 of your computer:

docker build . -t njuptaaa/judge_server --build-arg http_proxy=http://host.docker.internal:1080 --build-arg https_proxy=http://host.docker.internal:1080

If you are a resident of Chinese mainland, try using Dockerfile.cn, it is pre-configured to use some mirroring service:

docker build . -f Dockerfile.cn -t njuptaaa/judge_server

Babel Extension NOJ

NOJ JudgeServer is driven by Babel Extension NOJ, see Babel Extension NOJ and NOJ BABEL Github Public Mirror for more information.

All Supported Languages and Examples

Special Judge Support

SPJ Libraries

Starting from NOJ v0.18.0 and NOJ JudgeServer v0.3.0, NOJ JudgeServer provides a SPJ library called testlib, it contains some useful constants and definitions and it would be bundled as a optional SPJ library of C++.

Right now testlib would be the only SPJ library available but we are planning to support more SPJ libraries in the future.

SPJ Checker Languages

NOJ JudgeServer provides SPJ support for C language only prior to v0.3.0.

Starting from NOJ v0.18.0 and NOJ JudgeServer v0.3.0, NOJ JudgeServer provides additional support for C++ and PHP.

Migration from version prior to v0.3.0

Older versions of NOJ JudgeServer SPJs are feeded with testcase input and user output only. While in latest version of v0.3.0, It becomes testcase input, testcase output and user output. The changes not only grants testcase output access to SPJs, but also alters the given order. Thus all legacy version of SPJ need to:

1. Alter accepted argc to 4 and accepts testcase input as first, testcase output as second and user output as third;
2. Re-bundle testcases archive file to include .out files, then use NOJ v0.18.0 Admin Portal to re-upload the testcases, the .out files, if not needed, can be blank or simply the same as input.

SPJ sample code

SPJ Cheatsheet

Here lists all valid exit code for SPJ:

All unlisted exit codes would be viewed as System Error.

Since Linux only accepts last 8 bits of exit code, you can practically use -1 for System Error for it actually converts to 255. You can also use -255 (1) for Wrong Answer or -253 (3) for System Error, etc.

For C++ with testlib support, you can use testlib quitf function and macro defined _wa, _ok and so on without any conversion except Points and Partically Accepted status. NOJ Judge Server would recognize them properly and auto-convert them to NOJ JudgeServer standard.

For Points and Partically Accepted status, NOJ would verdict them all System Error no matter what score this SPJ actually nailed. For NOJ does not support single testcase with divided score.

We may support single-testcase-wide partically accepted status in the future.

Clang without any libraries

Here is a simple SPJ checker written in Clang, this checker checks if the integer user outputs equals the given testcase:

#include <stdio.h>

#define AC 0
#define WA 1
#define ERROR -1

int spj(FILE *input, FILE *output, FILE *user_output);

void close_file(FILE *f){
    if(f != NULL){
        fclose(f);
    }
}

int main(int argc, char *args[]){
    FILE *input = NULL, *output = NULL, *user_output = NULL;
    int result;
    if(argc != 4){
        printf("Usage: spj x.in x.out x.ans\n");
        return ERROR;
    }
    input = fopen(args[1], "r");
    output = fopen(args[2], "r");
    user_output = fopen(args[3], "r");
    if(input == NULL || output == NULL || user_output == NULL){
        printf("Failed to open output file\n");
        close_file(input);
        close_file(output);
        close_file(user_output);
        return ERROR;
    }

    result = spj(input, output, user_output);
    printf("result: %d\n", result);
    
    close_file(input);
    close_file(output);
    close_file(user_output);
    return result;
}

int spj(FILE *input, FILE *output, FILE *user_output){
    int a, b;
    fscanf(output, "%d", &b);
    if(~fscanf(user_output, "%d", &a)) {
        if(a == b){
            return AC;
        }
    }
    return WA;
}

C++ with testlib support

Here is a simple SPJ checker written in C++ with testlib support, this checker checks if the integer user outputs equals the given testcase:

#include <testlib>

int main(int argc, char * argv[]) {
    setName("compares two signed integers");
    registerTestlibCmd(argc, argv);
    int ja = ans.readInt();
    int pa = ouf.readInt();
    if (ja != pa) quitf(_wa, "expected %d, found %d", ja, pa);
    quitf(_ok, "answer is %d", ja);
}

PHP SPJ Support

NOJ JudgeServer Provides exclusive php language SPJ supports for contest arrangers to be benefited from this dynamic, weakly typed and artistic language, this checker checks if the integer user outputs equals the given testcase:

<?php

class Judge
{
    private const ACCEPTED = 0;
    private const WRONG_ANSWER = 1;
    private const SYSTEM_ERROR = -1;

    private $input = false;
    private $output = false;
    private $user_output = false;

    private $verdict = null;

    private function settleVerdict(int $ret = 0): void
    {
        if ($this->input !== false) {
            fclose($this->input);
        }
        if ($this->output !== false) {
            fclose($this->output);
        }
        if ($this->user_output !== false) {
            fclose($this->user_output);
        }
        $this->verdict = $ret;
    }

    public function __construct($argc, $argv)
    {
        if ($argc != 4) {
            printf("Usage: php {$argv[0]} x.in x.out x.ans\n");
            $this->settleVerdict(Judge::SYSTEM_ERROR);
            return;
        }

        $this->input = fopen($argv[1], "r");
        $this->output = fopen($argv[2], "r");
        $this->user_output = fopen($argv[3], "r");

        if ($this->input === false || $this->output === false || $this->user_output === false) {
            printf("Failed to open output file\n");
            $this->settleVerdict(Judge::SYSTEM_ERROR);
            return;
        }
    }

    public static function register($argc, $argv): Judge
    {
        return new Judge($argc, $argv);
    }

    private function judge(): int
    {
        fscanf($this->output, "%d", $b);
        if (fscanf($this->user_output, "%d", $a) !== false) {
            if ($a == $b) {
                return Judge::ACCEPTED;
            }
        }
        return Judge::WRONG_ANSWER;
    }

    public function getVerdict(): int
    {
        return $this->verdict ?? $this->judge();
    }
}

exit(Judge::register($argc, $argv)->getVerdict());