Training & Judge Center - Platform Configuration

This document defines the global configuration for the Training & Judge Center platform.

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Virtual Object Configuration

The Virtual Object contains platform-wide settings that constrain problem limits, sandbox configuration, and other global parameters. These settings are static and require a deployment to change (for security reasons).

Time and Memory Limits

{
  "maxTimeLimitGlobal": 300000,
  "maxMemoryLimitGlobal": 2048,
  "languageOverrides": [
    { "language": "cpp20", "maxTimeLimit": 300000, "maxMemoryLimit": 2048 },
    { "language": "java17", "maxTimeLimit": 400000, "maxMemoryLimit": 2048 },
    { "language": "python310", "maxTimeLimit": 600000, "maxMemoryLimit": 2048 }
  ]
}

Field	Type	Description
maxTimeLimitGlobal	integer	Maximum time limit in milliseconds that can be set as the default for a problem (applies to all languages unless overridden)
maxMemoryLimitGlobal	integer	Maximum memory limit in MiB that can be set as the default for a problem (applies to all languages unless overridden)
languageOverrides	array	Language-specific maximum limits. Allows certain languages (e.g., interpreted languages) to have higher maximum limits.

Language-Specific Overrides

Each entry in the languageOverrides array can specify:

Field	Type	Required	Description
language	string	Yes	Language identifier (e.g., cpp20, java17, python310)
maxTimeLimit	integer	No	Maximum time limit in milliseconds for this specific language
maxMemoryLimit	integer	No	Maximum memory limit in MiB for this specific language

How Limits Work

1. Problem Default Limits: When creating/updating a problem, timeLimit and memoryLimit define the default limits for all languages. These must not exceed maxTimeLimitGlobal and maxMemoryLimitGlobal.

2. Problem Language Overrides: Problems can specify languageOverrides to set different limits for specific languages. Each override must not exceed the corresponding maximum from the Virtual Object's languageOverrides for that language.

3. Validation Flow:

   • problem.timeLimit ≤ virtualObject.maxTimeLimitGlobal
   • problem.memoryLimit ≤ virtualObject.maxMemoryLimitGlobal
   • For each entry in problem.languageOverrides:
     • entry.timeLimit ≤ virtualObject.languageOverrides[entry.language].maxTimeLimit
     • entry.memoryLimit ≤ virtualObject.languageOverrides[entry.language].maxMemoryLimit

Example: Creating a Problem with Limits

{
  "title": "Sum of Two Numbers",
  "statement": "Given two integers a and b, return their sum.",
  "timeLimit": 2000,
  "memoryLimit": 256,
  "languageOverrides": [
    { "language": "python310", "timeLimit": 4000 },
    { "language": "java17", "memoryLimit": 512 }
  ]
}

In this example:

• C++ submissions use: 2000ms, 256 MiB (defaults)
• Python submissions use: 4000ms, 256 MiB (time overridden)
• Java submissions use: 2000ms, 512 MiB (memory overridden)

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Sandbox Configuration (Static)

The sandbox configuration defines security-critical settings for code execution. These settings are static and require a deployment to change to prevent accidental or malicious misconfiguration.

{
  "sandbox": {
    "path": "/sandbox",
    "sizeMB": 64,
    "useTmpfs": true,
    "maxOutputSizeMB": 64,
    "maxProcesses": 1,
    "networkEnabled": false,
    "readOnlyFilesystem": true
  },
  "compilation": {
    "timeoutSeconds": 30,
    "memoryLimitMB": 512,
    "outputLimitMB": 10
  },
  "checker": {
    "timeoutSeconds": 30
  }
}

Field	Type	Description
sandbox.path	string	Directory where user code executes (only writable location)
sandbox.sizeMB	integer	Maximum size of sandbox directory (tmpfs limit)
sandbox.useTmpfs	boolean	If true, sandbox uses RAM-based tmpfs for faster I/O and instant cleanup
sandbox.maxOutputSizeMB	integer	Maximum size of user program output
sandbox.maxProcesses	integer	Maximum number of processes (1 = no fork bombs)
sandbox.networkEnabled	boolean	Whether network access is allowed (always false for security)
sandbox.readOnlyFilesystem	boolean	Whether filesystem is read-only except /sandbox
compilation.timeoutSeconds	integer	Maximum time for compilation phase
compilation.memoryLimitMB	integer	Maximum memory for compilation
compilation.outputLimitMB	integer	Maximum compilation log size
checker.timeoutSeconds	integer	Maximum time for custom checker execution

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Supported Languages

Each language has a dedicated container image that may include multiple compiler versions.

C++ Family (image: judge-runner:cpp)

Language ID	Compiler	Compile Command	Run Command
cpp17	g++ 12	g++ -std=c++17 -O2 -o solution solution.cpp	./solution
cpp20	g++ 12	g++ -std=c++20 -O2 -o solution solution.cpp	./solution

Java Family (image: judge-runner:java)

Language ID	Compiler	Compile Command	Run Command
java17	javac 17	javac -encoding UTF-8 Solution.java	java Solution

Python Family (image: judge-runner:python)

Language ID	Interpreter	Syntax Check	Run Command
python310	pypy3	pypy3 -m py_compile solution.py	pypy3 solution.py

Note: Additional languages and versions may be added in the future. Each language family shares a container image for efficient resource usage. The platform validates that languageOverrides entries have valid language identifiers.

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Related Specifications

• Create Problem
• Update Problem
• Judge Submission