### ConfigNode get() Example

Source: https://github.com/dmoj/judge-server/blob/master/_autodocs/api-reference/config.md

Example of using the get() method with a default value.

```python
points = node.get('points', 1)
```

--------------------------------

### Starting Judge with API

Source: https://github.com/dmoj/judge-server/blob/master/_autodocs/configuration.md

Example command to start the judge server with the API enabled and listening on a specific port.

```bash
dmoj -c judge.yml -a 9998 -A 0.0.0.0 localhost
```

--------------------------------

### Compile and Execute example

Source: https://github.com/dmoj/judge-server/blob/master/_autodocs/api-reference/executors.md

A comprehensive example showing how to load executors, get an executor instance, compile source code, and launch it with resource limits.

```python
from dmoj import executors
import subprocess

# Load executors
executors.load_executors()

# Get executor
cpp = executors.executors['CPP17'].Executor

# Create executor instance
executor = cpp(
    problem_id='test',
    source_code=b'int main() { return 0; }',
    fs=[],  # Filesystem rules
)

# Compile
executor = executor.compile()

# Launch with resource limits
process = executor.launch(
    time=1.0,  # 1 second
    memory=65536,  # 64 MB
    stdin=open('input.txt', 'rb'),
    stdout=subprocess.PIPE,
    stderr=subprocess.PIPE,
)

# Wait for completion
stdout, stderr = process.communicate()
print(f"Exit code: {process.returncode}")
```

--------------------------------

### LocalJudge Example

Source: https://github.com/dmoj/judge-server/blob/master/_autodocs/api-reference/cli.md

Example of initializing LocalJudge and preparing to start the CLI loop.

```python
from dmoj.cli import LocalJudge

judge = LocalJudge()
# Now use judge.listen() to start CLI loop

```

--------------------------------

### submit / test Example

Source: https://github.com/dmoj/judge-server/blob/master/_autodocs/api-reference/cli.md

Example commands for submitting and testing solutions.

```bash
dmoj-cli> submit aplusb CPP17 /home/user/solution.cpp
dmoj-cli> test myprob PY3 solution.py

```

--------------------------------

### validate Command Example

Source: https://github.com/dmoj/judge-server/blob/master/_autodocs/api-reference/cli.md

Example command to validate a problem setup.

```bash
dmoj-cli> validate aplusb

```

--------------------------------

### help Command Example

Source: https://github.com/dmoj/judge-server/blob/master/_autodocs/api-reference/cli.md

Example commands for using the 'help' command.

```bash
help [command]

dmoj-cli> help submit
dmoj-cli> help

```

--------------------------------

### GET /metrics Example

Source: https://github.com/dmoj/judge-server/blob/master/_autodocs/endpoints.md

Examples of how to fetch metrics using curl, Python, and Prometheus configuration.

```bash
# Using curl
curl http://judge-host:9998/metrics
```

```python
# Using Python
import requests
response = requests.get('http://judge-host:9998/metrics')
print(response.text)
```

```yaml
# In monitoring systems (Prometheus)
scrape_configs:
  - job_name: 'dmoj-judge'
    static_configs:
      - targets: ['judge-host:9998']
```

--------------------------------

### ConfigNode unwrap() Example

Source: https://github.com/dmoj/judge-server/blob/master/_autodocs/api-reference/config.md

Example of unwrapping a ConfigNode to get the raw dictionary.

```python
raw = node.unwrap()
```

--------------------------------

### show Command Example

Source: https://github.com/dmoj/judge-server/blob/master/_autodocs/api-reference/cli.md

Example command to display problem information.

```bash
dmoj-cli> show aplusb

```

--------------------------------

### run Method Example

Source: https://github.com/dmoj/judge-server/blob/master/_autodocs/api-reference/packet.md

Example of calling the run method.

```python
pm.run()  # Blocking call
```

--------------------------------

### Example of using by_ext

Source: https://github.com/dmoj/judge-server/blob/master/_autodocs/api-reference/executors.md

Shows how to get executors for C++ and Java using their file extensions.

```python
cpp_executor = executors.by_ext('cpp')  # CPP17, CPP14, etc.
java_executor = executors.by_ext('java')  # JAVA8 or JAVA
```

--------------------------------

### launch Method Example

Source: https://github.com/dmoj/judge-server/blob/master/_autodocs/api-reference/executors.md

Example of launching an executor with resource limits.

```python
process = executor.launch(
    time=2.0,
    memory=65536,
    stdin=subprocess.PIPE,
    stdout=subprocess.PIPE,
    stderr=subprocess.PIPE,
)
```

--------------------------------

### get_problem_root Function Example

Source: https://github.com/dmoj/judge-server/blob/master/_autodocs/api-reference/config.md

Example showing how to get the root directory path for a specific problem.

```python
root = judgeenv.get_problem_root('aplusb')
print(root)  # /problems/aplusb
```

--------------------------------

### Filesystem Configuration Example

Source: https://github.com/dmoj/judge-server/blob/master/_autodocs/configuration.md

Example of configuring filesystem access rules for different languages (Perl and Ruby).

```yaml
extra_fs:
  PERL:
    - exact_file: /dev/dtrace/helper
    - recursive_dir: /usr/share/perl
  RUBY:
    - exact_dir: /usr/lib/ruby
    - recursive_dir: /usr/share/ruby
```

--------------------------------

### Getting Metrics

Source: https://github.com/dmoj/judge-server/blob/master/_autodocs/configuration.md

Example curl command to retrieve Prometheus metrics from the Judge API.

```bash
curl http://localhost:9998/metrics
```

--------------------------------

### Server Mode Examples

Source: https://github.com/dmoj/judge-server/blob/master/_autodocs/configuration.md

Examples demonstrating how to connect the DMOJ judge to a server using various configurations, including TLS and debug mode.

```bash
# Connect to judge server
dmoj -c /etc/judge.yml -p 9999 judge.example.com judge-1 secret-key

# With TLS
dmoj -c /etc/judge.yml -s -T /etc/ssl/certs/ca.pem judge.example.com:9999

# Debug mode with limited executors
dmoj -c /etc/judge.yml -d -e CPP17,JAVA8 localhost

```

--------------------------------

### Item Access Example

Source: https://github.com/dmoj/judge-server/blob/master/_autodocs/api-reference/config.md

Example of accessing a configuration key using item access.

```python
node['key-name']
node[0]  # For lists
```

--------------------------------

### InvalidInitException Constructor and Example

Source: https://github.com/dmoj/judge-server/blob/master/_autodocs/api-reference/config.md

Demonstrates the constructor signature and provides an example of catching the InvalidInitException.

```python
InvalidInitException(message: str)
```

```python
try:
    problem = Problem('nonexistent', 1.0, 65536, {})
except InvalidInitException as e:
    print(f"Failed to load problem: {e}")
```

--------------------------------

### ConfigNode Example

Source: https://github.com/dmoj/judge-server/blob/master/_autodocs/api-reference/config.md

Example usage of ConfigNode with a configuration dictionary.

```python
from dmoj.config import ConfigNode

config_dict = {
    'output_prefix_length': 5,
    'test_cases': [
        {'in': 'test1.in', 'out': 'test1.out', 'points': 10},
        {'in': 'test2.in', 'out': 'test2.out', 'points': 20}
    ]
}

node = ConfigNode(config_dict)
print(node.output_prefix_length)  # 5
print(node['test_cases'][0]['points'])  # 10
```

--------------------------------

### Example of using from_filename

Source: https://github.com/dmoj/judge-server/blob/master/_autodocs/api-reference/executors.md

Demonstrates getting an executor from a given filename.

```python
executor_module = executors.from_filename('solution.cpp')
executor_module = executors.from_filename('Main.java')
```

--------------------------------

### get_runtime_versions Function Example

Source: https://github.com/dmoj/judge-server/blob/master/_autodocs/api-reference/config.md

Example demonstrating how to fetch and display available runtime versions for different executors.

```python
versions = judgeenv.get_runtime_versions()
if 'CPP17' in versions:
    for version_str, version_tuple in versions['CPP17']:
        print(f"C++ 17: {version_str}")
```

--------------------------------

### Dynamic Keys - Full Code Example

Source: https://github.com/dmoj/judge-server/blob/master/_autodocs/api-reference/config.md

Example of dynamic key evaluation using full code execution in YAML.

```yaml
time_limit++: |
  exec("""
  node['time_limit'] = get_time_limit(node)
  """)
```

--------------------------------

### PacketManager Example

Source: https://github.com/dmoj/judge-server/blob/master/_autodocs/api-reference/packet.md

Example of how to instantiate and configure a PacketManager.

```python
from dmoj.packet import PacketManager
from dmoj.judge import Judge

judge = Judge(None)  # Will be set
pm = PacketManager(
    host='judge.example.com',
    port=9999,
    judge=judge,
    name='judge-1',
    key='secret-key',
    secure=True
)
judge.packet_manager = pm
```

--------------------------------

### CLI Mode Examples

Source: https://github.com/dmoj/judge-server/blob/master/_autodocs/configuration.md

Examples demonstrating how to use the DMOJ judge in CLI mode, including interactive mode and running a single command.

```bash
# Interactive CLI
dmoj-cli -c /etc/judge.yml

# Run single command
dmoj-cli -c /etc/judge.yml submit aplusb CPP17 /path/to/solution.cpp

```

--------------------------------

### resubmit Command Example

Source: https://github.com/dmoj/judge-server/blob/master/_autodocs/api-reference/cli.md

Example command to re-submit a solution with the same code.

```bash
dmoj-cli> resubmit 5

```

--------------------------------

### get_supported_problems_and_mtimes Function Example

Source: https://github.com/dmoj/judge-server/blob/master/_autodocs/api-reference/config.md

Example of how to retrieve a dictionary of supported problems and their last modification times.

```python
problems = judgeenv.get_supported_problems_and_mtimes()
for problem_id, mtime in problems.items():
    print(f"{problem_id}: modified at {mtime}")
```

--------------------------------

### ConfigNode items() Example

Source: https://github.com/dmoj/judge-server/blob/master/_autodocs/api-reference/config.md

Example of iterating over key-value pairs using the items() method.

```python
for key, value in node.items():
    print(f"{key}: {value}")
```

--------------------------------

### Judge.listen Example

Source: https://github.com/dmoj/judge-server/blob/master/_autodocs/api-reference/judge.md

Starts the judge event loop. Attempts to connect to the judge server and process submissions.

```python
try:
    judge.listen()
except KeyboardInterrupt:
    pass
```

--------------------------------

### ConfigNode update() Example

Source: https://github.com/dmoj/judge-server/blob/master/_autodocs/api-reference/config.md

Example of updating a ConfigNode with new key-value pairs.

```python
node.update({'points': 100})
```

--------------------------------

### ProblemDataManager.open Example

Source: https://github.com/dmoj/judge-server/blob/master/_autodocs/api-reference/problem.md

Example of how to use the open method to read a file.

```python
with problem_data.open('input.txt') as f:
    data = f.read()
```

--------------------------------

### CLI Environment Variables Example

Source: https://github.com/dmoj/judge-server/blob/master/_autodocs/api-reference/cli.md

Examples of running the DMOJ CLI with specific configurations or flags.

```bash
# Run a single command without interactive shell
dmoj-cli -c config.yml submit problem CPP17 solution.cpp

# With extended history file
dmoj-cli --history /tmp/judge_history -c config.yml

```

--------------------------------

### Dynamic Keys - Expression Evaluation Example

Source: https://github.com/dmoj/judge-server/blob/master/_autodocs/api-reference/config.md

Example demonstrating dynamic expression evaluation for a ConfigNode.

```python
config = {
    'points+': 'len(node["test_cases"]) * 10'
}
node = ConfigNode(config)
# node.points will be calculated dynamically
```

--------------------------------

### Attribute Access Example

Source: https://github.com/dmoj/judge-server/blob/master/_autodocs/api-reference/config.md

Example of accessing a configuration key using attribute access.

```python
node.key_name
```

--------------------------------

### CLI Configuration Example

Source: https://github.com/dmoj/judge-server/blob/master/_autodocs/api-reference/cli.md

Example configuration file (~/.dmojrc) for the DMOJ CLI.

```yaml
# Problem directories
problem_globs:
  - ~/problems/*

# CLI-specific settings
# (Most settings from server config still apply)

```

--------------------------------

### close Method Example

Source: https://github.com/dmoj/judge-server/blob/master/_autodocs/api-reference/packet.md

Example of calling the close method.

```python
pm.close()
```

--------------------------------

### Submission Object Construction Example

Source: https://github.com/dmoj/judge-server/blob/master/_autodocs/types.md

An example of how to construct a Submission object in Python.

```python
from dmoj.judge import Submission

submission = Submission(
    id=12345,
    problem_id='aplusb',
    language='CPP17',
    source='#include <iostream>\nint main() { int a, b; cin >> a >> b; cout << a+b; }',
    time_limit=1.0,
    memory_limit=65536,
    short_circuit=False,
    meta={'user': 'user123'}
)
```

--------------------------------

### load_env Function Example

Source: https://github.com/dmoj/judge-server/blob/master/_autodocs/api-reference/config.md

Example usage of the load_env function for both server and CLI modes.

```python
# Server mode
from dmoj import judgeenv
judgeenv.load_env(cli=False)
print(judgeenv.server_host)
print(judgeenv.env.compiler_time_limit)

# CLI mode
judgeenv.load_env(cli=True)
```

--------------------------------

### rejudge Command Example

Source: https://github.com/dmoj/judge-server/blob/master/_autodocs/api-reference/cli.md

Example command to re-grade a submission.

```bash
dmoj-cli> rejudge 5

```

--------------------------------

### Example Usage

Source: https://github.com/dmoj/judge-server/blob/master/contrib/vm-host-problem-watch/README.md

Demonstrates how to use the vm-host-problem-watch.sh script, including setting up a judge hosts list, listing problems, and running the script to watch for updates and notify judges.

```bash
$ cat /code/judge-hosts-list
judge1.example.com:9998
judge2.example.com:9998
judge3.example.com:9998
$ ls /export/problems | head -n 5
apio
bbc
bkoi
broi
btoi
$ ./vm-host-problem-watch.sh /export/problems /code/judge-host-list
Tue Oct  6 22:17:37 UTC 2020: Start watching /export/problems, notifying /code/judge-host-list
Tue Oct  6 22:17:46 UTC 2020: Update problems [/export/problems/rgss/17/rgpc17p5/ MOVED_FROM init.yml]
Tue Oct  6 22:17:46 UTC 2020 [judge1.example.com:9998]: As you wish.
Tue Oct  6 22:17:46 UTC 2020 [judge2.example.com:9998]: As you wish.
Tue Oct  6 22:17:46 UTC 2020 [judge3.example.com:9998]: As you wish.
```

--------------------------------

### Install stable build

Source: https://github.com/dmoj/judge-server/blob/master/README.md

Installs the DMOJ judge using pip.

```bash
$ pip install dmoj
```

--------------------------------

### diff Command Example

Source: https://github.com/dmoj/judge-server/blob/master/_autodocs/api-reference/cli.md

Example command to show verdict differences for a submission.

```bash
dmoj-cli> diff 5

```

--------------------------------

### ProblemConfig Example

Source: https://github.com/dmoj/judge-server/blob/master/_autodocs/api-reference/problem.md

Example of creating a ProblemConfig object and accessing its time_limit attribute.

```python
config = ProblemConfig(problem_data, meta={'source': 'contest'})
print(config.time_limit)  # From init.yml
```

--------------------------------

### Dynamic Keys - Expression Example

Source: https://github.com/dmoj/judge-server/blob/master/_autodocs/api-reference/config.md

Example of dynamic key evaluation using Python expressions in YAML.

```yaml
wall_time_factor+: 3
time_limit: 2
wall_time_factor+: "node['time_limit'] * 3"
```

--------------------------------

### Problem Configuration Example (init.yml)

Source: https://github.com/dmoj/judge-server/blob/master/_autodocs/types.md

An example YAML configuration file for defining a problem on the DMOJ judge server, including test cases, custom checkers, batched test cases, interactive problems, signature grading, custom judges, and various output/performance settings.

```yaml
# Required: Test cases
test_cases:
  - {in: input.txt, out: output.txt, points: 10}
  - {in: input2.txt, out: output2.txt, points: 20}

# Or with archive:
archive: problems.zip
test_cases:
  - {in: input.txt, out: output.txt, points: 10}

# Optional: Custom checker
checker:
  function: check

# Optional: Batched test cases (all-or-nothing)
test_cases:
  - batched:
      - {in: input1.txt, out: output1.txt}
      - {in: input2.txt, out: output2.txt}
    points: 15
  - {in: input3.txt, out: output3.txt, points: 10}

# Optional: Interactive problem
interactive:
  judge: interactor.cpp
  feedback: true

# Optional: Signature graded (C++ function)
signature_grader:
  entry: main
  header: header.h

# Optional: Custom judge
custom_judge: judge.cpp

# Optional: Output prefix length
output_prefix_length: 100

# Optional: Wall time factor (real time / cpu time)
wall_time_factor: 3

# Optional: Output size limit (bytes)
output_limit_length: 25165824

# Optional: Binary data (no newline normalization)
binary_data: false

# Optional: Short circuit (stop on first non-AC)
short_circuit: true

# Optional: Pretest cases
pretest_test_cases:
  - {in: pretest1.txt, out: pretest1.txt, points: 5}

```

--------------------------------

### Result Example

Source: https://github.com/dmoj/judge-server/blob/master/_autodocs/api-reference/result.md

An example demonstrating how to instantiate the Result class with specific values.

```python
result = Result(
    case=test_case,
    result_flag=Result.AC,
    execution_time=0.123,
    wall_clock_time=0.150,
    max_memory=5000,
    proc_output=b'42\n',
    points=test_case.points
)
```

--------------------------------

### Executor Configuration Example

Source: https://github.com/dmoj/judge-server/blob/master/_autodocs/configuration.md

Example of configuring executors, including version and flags for C++ and memory limit for Java.

```yaml
runtime:
  CPP17:
    version: 'g++ (Debian 10.2.0-5) 10.2.0'
    flags:
      - '-O2'
  JAVA8:
    memory_limit: 262144  # 256MB
```

--------------------------------

### output Property Example

Source: https://github.com/dmoj/judge-server/blob/master/_autodocs/api-reference/result.md

Example of printing the program output obtained from the output property.

```python
print(f"Output: {result.output}")
```

--------------------------------

### Integration Example

Source: https://github.com/dmoj/judge-server/blob/master/_autodocs/MANIFEST.md

An example demonstrating how to integrate the DMOJ judge using its documentation.

```python
# 1. Load configuration (see config.md)
from dmoj.judgeenv import load_env
load_env()

# 2. Create judge instance (see judge.md)
from dmoj.judge import Judge
from dmoj.packet import PacketManager

pm = PacketManager(
    host='judge.example.com',
    port=9999,
    judge=None,
    name='judge-1',
    key='secret-key'
)
judge = Judge(pm)
pm.judge = judge

# 3. Load languages (see executors.md)
from dmoj import executors
executors.load_executors()

# 4. Load problems (see problem.md)
from dmoj.problem import Problem
problem = Problem('test', 1.0, 65536, {})

```

--------------------------------

### Example of loading executors

Source: https://github.com/dmoj/judge-server/blob/master/_autodocs/api-reference/executors.md

Demonstrates how to load executors and print their keys.

```python
from dmoj import executors

executors.load_executors()
print(executors.executors.keys())  # [\'CPP17\', \'JAVA8\', \'PY3\', ...]
```

--------------------------------

### get_main_code Example

Source: https://github.com/dmoj/judge-server/blob/master/_autodocs/api-reference/result.md

Example usage of the get_main_code method to check if a result is Accepted.

```python
main_verdict = result.get_main_code()
if main_verdict == Result.AC:
    print("Correct!")
```

--------------------------------

### LocalPacketManager Example

Source: https://github.com/dmoj/judge-server/blob/master/_autodocs/api-reference/cli.md

Demonstrates the usage of LocalPacketManager within LocalJudge, highlighting its no-op nature.

```python
from dmoj.cli import LocalPacketManager, LocalJudge

judge = LocalJudge()
pm = judge.packet_manager
pm.test_case_status_packet(0, result)  # Does nothing
```

--------------------------------

### POST /update/problems Example

Source: https://github.com/dmoj/judge-server/blob/master/_autodocs/endpoints.md

Examples of how to trigger the POST /update/problems endpoint using curl and Python.

```bash
# Using curl
curl -X POST http://judge-host:9998/update/problems
```

```python
# In Python
import requests
response = requests.post('http://judge-host:9998/update/problems')
assert response.status_code == 200
```

--------------------------------

### Example judge.yml

Source: https://github.com/dmoj/judge-server/blob/master/_autodocs/configuration.md

A comprehensive example of a judge.yml configuration file, illustrating various settings for judge name, authentication, problem directories, compilation, testing, and runtime environments.

```yaml
# Judge name and authentication
# (Can be overridden via command line)
judge_name: judge-1
judge_key: secret-key-123

# Problem directories (glob patterns)
# Multiple patterns can be specified
problem_globs:
  - /problems/*
  - /extra-problems/*

# Watch for problem directory changes
problem_watches:
  - /problems

# Regex filters for problems and cases
# (Used in testing/debug mode)
# problem_regex: pattern
# case_regex: pattern

# Temporary directory for compilation and execution
# Defaults to system temp directory
tempdir: /tmp/judge

# Compiler configuration
compiler_time_limit: 10        # Seconds
compiler_size_limit: 131072    # KB (128MB)
compiler_output_character_limit: 65536

# Compiled binary cache
compiled_binary_cache_dir: /var/cache/judge/binaries
compiled_binary_cache_size: 100  # LRU

# Test runner configuration
selftest_time_limit: 10        # Seconds
selftest_memory_limit: 131072  # KB (128MB)

# Generator configuration
generator_compiler_time_limit: 30  # Seconds
generator_time_limit: 20           # Seconds
generator_memory_limit: 524288     # KB (512MB)

# Validator configuration
validator_compiler_time_limit: 30  # Seconds
validator_time_limit: 20           # Seconds
validator_memory_limit: 524288     # KB (512MB)

# CPU affinity (list of core IDs, or null for any)
# submission_cpu_affinity: [0, 1, 2, 3]
submission_cpu_affinity: null

# Per-executor runtime configuration
runtime:
  CPP17:
    # Executor-specific options
  JAVA8:
    # Executor-specific options

# Per-executor filesystem configuration
extra_fs:
  PERL:
    - exact_file: /dev/dtrace/helper
  RUBY:
    - recursive_dir: /usr/lib/ruby
    - exact_dir: /usr/share/ruby

# Update notification URLs
# Judge will POST to /update/problems on these URLs
update_pings:
  - http://main-judge:9998
  - http://backup-judge:9998

```

--------------------------------

### Start Judge with API

Source: https://github.com/dmoj/judge-server/blob/master/_autodocs/endpoints.md

Command to start the DMOJ judge server with API enabled, listening on a specific port and host.

```bash
dmoj -c judge.yml -a 9998 -A 0.0.0.0 server.example.com judge-name key
```

--------------------------------

### submit / test Command Usage

Source: https://github.com/dmoj/judge-server/blob/master/_autodocs/api-reference/cli.md

Usage examples for the 'submit' and 'test' CLI commands.

```bash
submit <problem_id> <language> <source_file>
test <problem_id> <language> <source_file>

```

--------------------------------

### InvalidInitException Example

Source: https://github.com/dmoj/judge-server/blob/master/_autodocs/errors.md

Demonstrates handling InvalidInitException during problem initialization.

```python
from dmoj.problem import Problem
from dmoj.config import InvalidInitException

try:
    problem = Problem('nonexistent', 1.0, 65536, {})
except InvalidInitException as e:
    print(f"Invalid problem: {e}")
    judge.log_internal_error(message=str(e))
```

--------------------------------

### Example CLI Workflow

Source: https://github.com/dmoj/judge-server/blob/master/_autodocs/api-reference/cli.md

Illustrates a typical command-line interaction with the DMOJ CLI, from listing problems to submitting a solution and viewing submissions.

```bash
$ dmoj-cli -c ~/.dmojrc

Running local judge...

dmoj> problems
Problem ID | Time Limit | Memory Limit | Cases
-----------|------------|--------------|-------
aplusb     | 1.0 s      | 64 MB        | 5
sum        | 2.0 s      | 128 MB       | 10

dmoj> show aplusb
Problem: aplusb (A Plus B)
Time Limit: 1.0 seconds
Memory Limit: 64 MB
Test Cases: 5
Checker: standard

dmoj> submit aplusb CPP17 /tmp/solution.cpp
Start grading #ansi[aplusb](#yellow)/#ansi[0](green|bold) in CPP17...

Test case  0 AC [0.001s (0.002s wall) | 1024kb | 0 switches]
Test case  1 AC [0.001s (0.002s wall) | 1024kb | 0 switches]
Test case  2 AC [0.001s (0.002s wall) | 1024kb | 0 switches]
Test case  3 AC [0.002s (0.003s wall) | 2048kb | 1 switches]
Test case  4 AC [0.001s (0.002s wall) | 1024kb | 0 switches]

Done grading aplusb/0.

dmoj> submissions
ID | Problem | Language | Verdict | Points | Time
---|---------|----------|---------|--------|------
 0 | aplusb  | CPP17    | AC      | 5/5    | 0.008

dmoj> exit
```

--------------------------------

### StandardGrader Example Usage

Source: https://github.com/dmoj/judge-server/blob/master/_autodocs/api-reference/graders.md

Example of how to instantiate and use the StandardGrader to grade a test case.

```python
from dmoj.graders.standard import StandardGrader

grader = StandardGrader(judge_worker, problem, 'CPP17', source_code)
result = grader.grade(test_case)
print(f"Verdict: {result.get_main_code()}")
print(f"Points: {result.points}")
```

--------------------------------

### Import Examples

Source: https://github.com/dmoj/judge-server/blob/master/_autodocs/README.md

Examples of common imports for the DMOJ judge server, covering various modules like judge, problems, grading, configuration, network, executors, CLI, and errors.

```python
# Main judge
from dmoj.judge import Judge, Submission, JudgeWorker

# Problems and test cases
from dmoj.problem import Problem, TestCase, BatchedTestCase

# Grading
from dmoj.graders import StandardGrader, InteractiveGrader
from dmomoj.result import Result, CheckerResult

# Configuration
from dmoj.config import ConfigNode
from dmoj.judgeenv import env, load_env

# Network
from dmoj.packet import PacketManager

# Executors
from dmoj.executors import load_executors
from dmoj.executors.base_executor import BaseExecutor

# CLI
from dmoj.cli import LocalJudge, cli_main

# Errors
from dmoj.error import CompileError, InternalError
from dmoj.config import InvalidInitException
```

--------------------------------

### Example Alert Rules (alert.rules.yml)

Source: https://github.com/dmoj/judge-server/blob/master/_autodocs/endpoints.md

Example Prometheus alert rules defined in an alert.rules.yml file for DMOJ judge monitoring.

```yaml
groups:
  - name: dmoj_judge
    interval: 30s
    rules:
      - alert: JudgeDown
        expr: dmoj_judge_up == 0
        for: 5m
        annotations:
          summary: "Judge {{ $labels.instance }} is down"

      - alert: JudgeBacklog
        expr: rate(dmoj_judge_submission_graded_total[5m]) < 0.1
        for: 10m
        annotations:
          summary: "Judge {{ $labels.instance }} is not grading"

      - alert: HighErrorRate
        expr: |
          (
            increase(dmoj_judge_case_verdicts_total{verdict=~"IE|RTE"}[1h])
          ) > 100
        annotations:
          summary: "High error rate on judge {{ $labels.instance }}"
```

--------------------------------

### Example Prometheus Configuration

Source: https://github.com/dmoj/judge-server/blob/master/_autodocs/endpoints.md

A sample YAML configuration for Prometheus to scrape metrics from the DMOJ judge server.

```yaml
global:
  scrape_interval: 15s

scrape_configs:
  - job_name: 'dmoj-judge'
    scrape_interval: 5s
    static_configs:
      - targets: ['localhost:9998']
    relabel_configs:
      - source_labels: [__address__]
        target_label: instance

# Alert rules example
alerting:
  alertmanagers:
    - static_configs:
        - targets: ['localhost:9093']

rule_files:
  - 'alert.rules.yml'
```

--------------------------------

### OutputLimitExceeded Example

Source: https://github.com/dmoj/judge-server/blob/master/_autodocs/errors.md

Illustrates catching an OutputLimitExceeded error when submission output exceeds limits.

```python
from dmoj.error import OutputLimitExceeded

try:
    # Process output
    if len(output) > output_limit:
        raise OutputLimitExceeded('stdout', output_limit)
except OutputLimitExceeded as e:
    print(f"Error: {e}")
    result.result_flag |= Result.OLE
```

--------------------------------

### Contrib Module Loading Example

Source: https://github.com/dmoj/judge-server/blob/master/_autodocs/api-reference/contrib-modules.md

Python code snippet demonstrating how to load all available contrib modules.

```python
from dmoj import contrib

# Load all available contrib modules
contrib.load_contrib_modules()
```

--------------------------------

### BaseContribModule parse_return_code Example Implementation

Source: https://github.com/dmoj/judge-server/blob/master/_autodocs/api-reference/contrib-modules.md

Example implementation of the parse_return_code class method for a custom module, handling Accepted and Wrong Answer verdicts.

```python
class MyModule(BaseContribModule):
    name = 'mymodule'
    AC = 0
    WA = 1
    
    @classmethod
    def parse_return_code(cls, proc, executor, point_value, time_limit, memory_limit, feedback, name, stderr):
        if proc.returncode == cls.AC:
            return CheckerResult(True, point_value)
        elif proc.returncode == cls.WA:
            return CheckerResult(False, 0)
        else:
            return CheckerResult(False, 0, feedback=f'{name} crashed}')
```

--------------------------------

### TestLib Module Example Checker (C++)

Source: https://github.com/dmoj/judge-server/blob/master/_autodocs/api-reference/contrib-modules.md

Example of a checker program written in C++ using the testlib library to compare output with the answer.

```cpp
#include "testlib.h"
#include <string>

int main(int argc, char** argv) {
    registerTestlibCmd(argc, argv);
    
    string output = ouf.readString();
    string answer = ans.readString();
    
    if (output == answer) {
        quitf(_ok, "Correct!");
    } else {
        quitf(_wa, "Expected %s, got %s", answer.c_str(), output.c_str());
    }
    
    return 0;
}
```

--------------------------------

### InvalidCommandException Example

Source: https://github.com/dmoj/judge-server/blob/master/_autodocs/errors.md

Shows how to raise and catch an InvalidCommandException for CLI argument errors.

```python
from dmoj.error import InvalidCommandException

try:
    if not isinstance(points, float):
        raise InvalidCommandException("Points must be a number")
except InvalidCommandException as e:
    if e.message:
        print(f"Error: {e.message}")
```

--------------------------------

### Judge Server Listening Endpoint

Source: https://github.com/dmoj/judge-server/blob/master/_autodocs/MANIFEST.md

This snippet shows the basic command to start the judge server listening.

```python
judge.listen()
```

--------------------------------

### Judge.begin_grading Example

Source: https://github.com/dmoj/judge-server/blob/master/_autodocs/api-reference/judge.md

Begins grading a submission. Creates a JudgeWorker and spawns a grading thread.

```python
from dmoj.judge import Submission, Judge

submission = Submission(
    id=123,
    problem_id='aplusb',
    language='CPP17',
    source='#include <iostream>\nint main() { int a, b; cin >> a >> b; cout << a+b; }',
    time_limit=1.0,
    memory_limit=65536,
    short_circuit=False,
    meta={}
)

judge.begin_grading(submission, blocking=False)
```

--------------------------------

### run Method

Source: https://github.com/dmoj/judge-server/blob/master/_autodocs/api-reference/packet.md

Signature for the run method, which starts the packet manager's event loop.

```python
def run(self) -> None
```

--------------------------------

### readable_codes Example

Source: https://github.com/dmoj/judge-server/blob/master/_autodocs/api-reference/result.md

Example of using readable_codes to display all applicable verdicts.

```python
verdicts = result.readable_codes()
# Returns ['TLE', 'RTE'] if both flags are set
```

--------------------------------

### Install bleeding-edge build

Source: https://github.com/dmoj/judge-server/blob/master/README.md

Installs the bleeding-edge version of the DMOJ judge from source.

```bash
$ git clone --recursive https://github.com/DMOJ/judge-server.git
$ cd judge-server
$ pip install -e .
```

--------------------------------

### BaseGrader.abort_grading Method Example

Source: https://github.com/dmoj/judge-server/blob/master/_autodocs/api-reference/graders.md

Example of how to call the abort_grading method on a grader instance.

```python
grader.abort_grading()
```

--------------------------------

### BaseContribModule get_checker_args_format_string Example

Source: https://github.com/dmoj/judge-server/blob/master/_autodocs/api-reference/contrib-modules.md

Example implementation of the get_checker_args_format_string class method for a custom checker module.

```python
class MyModule(BaseContribModule):
    @classmethod
    def get_checker_args_format_string(cls) -> str:
        return '{input} {output} {submission_output}'
```

--------------------------------

### Example Custom Checker

Source: https://github.com/dmoj/judge-server/blob/master/_autodocs/api-reference/graders.md

An example of a custom checker function that compares stripped actual and expected output, returning a CheckerResult.

```python
from dmoj.result import CheckerResult

def check(process_output: bytes, expected_output: bytes, **kwargs) -> CheckerResult:
    actual = process_output.decode().strip()
    expected = expected_output.decode().strip()
    
    if actual == expected:
        return CheckerResult(True, kwargs['point_value'])
    else:
        return CheckerResult(False, 0, f"Expected {expected}, got {actual}")
```

--------------------------------

### launch Method

Source: https://github.com/dmoj/judge-server/blob/master/_autodocs/api-reference/executors.md

Launches the compiled program with resource limits.

```python
def launch(
    self,
    time: float = 2,
    memory: int = 65536,
    stdin: IO = None,
    stdout: IO = None,
    stderr: IO = None,
    wall_time: float = None,
    symlinks: Dict[str, str] = None,
) -> TracedPopen:
```

--------------------------------

### Problem Constructor

Source: https://github.com/dmoj/judge-server/blob/master/_autodocs/api-reference/problem.md

Initializes a new Problem instance.

```python
problem = Problem(
    problem_id='aplusb',
    time_limit=1.0,
    memory_limit=65536,
    meta={}
)
```

--------------------------------

### TestCase Constructor

Source: https://github.com/dmoj/judge-server/blob/master/_autodocs/api-reference/problem.md

Initializes a new TestCase instance.

```python
TestCase(
    count: int,
    batch_no: int,
    config: ConfigNode,
    problem: Problem
) -> None
```

--------------------------------

### Judge.abort_grading Example

Source: https://github.com/dmoj/judge-server/blob/master/_autodocs/api-reference/judge.md

Aborts the currently grading submission.

```python
judge.abort_grading(submission_id=123)
```

--------------------------------

### CLI Command Format

Source: https://github.com/dmoj/judge-server/blob/master/_autodocs/api-reference/cli.md

General format for DMOJ CLI commands.

```bash
dmoj-cli> command [arguments]

```

--------------------------------

### InternalError Example

Source: https://github.com/dmoj/judge-server/blob/master/_autodocs/errors.md

Shows how to raise an InternalError for unexpected issues during grading.

```python
from dmoj.error import InternalError

try:
    # Grading logic
except Exception as e:
    raise InternalError(f"Unexpected error during grading: {e}")
```

--------------------------------

### DMOJ Judge Server CLI Help

Source: https://github.com/dmoj/judge-server/blob/master/README.md

Displays the help message for the 'dmoj' command, outlining its usage and available arguments for running a judge server.

```bash
$ dmoj --help
usage: dmoj [-h] [-p SERVER_PORT] -c CONFIG [-l LOG_FILE] [--no-watchdog]
            [-a API_PORT] [-A API_HOST] [-s] [-k] [-T TRUSTED_CERTIFICATES]
            [-e ONLY_EXECUTORS | -x EXCLUDE_EXECUTORS] [--no-ansi]
            server_host [judge_name] [judge_key]

Spawns a judge for a submission server.

positional arguments:
  server_host           host to connect for the server
  judge_name            judge name (overrides configuration)
  judge_key             judge key (overrides configuration)

optional arguments:
  -h, --help            show this help message and exit
  -p SERVER_PORT, --server-port SERVER_PORT
                        port to connect for the server
  -c CONFIG, --config CONFIG
                        file to load judge configurations from
  -l LOG_FILE, --log-file LOG_FILE
                        log file to use
  --no-watchdog         disable use of watchdog on problem directories
  -a API_PORT, --api-port API_PORT
                        port to listen for the judge API (do not expose to
                        public, security is left as an exercise for the
                        reverse proxy)
  -A API_HOST, --api-host API_HOST
                        IPv4 address to listen for judge API
  -s, --secure          connect to server via TLS
  -k, --no-certificate-check
                        do not check TLS certificate
  -T TRUSTED_CERTIFICATES, --trusted-certificates TRUSTED_CERTIFICATES
                        use trusted certificate file instead of system
  -e ONLY_EXECUTORS, --only-executors ONLY_EXECUTORS
                        only listed executors will be loaded (comma-separated)
  -x EXCLUDE_EXECUTORS, --exclude-executors EXCLUDE_EXECUTORS
                        prevent listed executors from loading (comma-
                        separated)
  --no-ansi             disable ANSI output
  --skip-self-test      skip executor self-tests
```

--------------------------------

### CompileError Example

Source: https://github.com/dmoj/judge-server/blob/master/_autodocs/errors.md

Demonstrates how to catch and handle a CompileError during the grading process.

```python
from dmoj.error import CompileError
from dmoj.graders.standard import StandardGrader

try:
    grader = StandardGrader(judge_worker, problem, 'CPP17', source)
except CompileError as e:
    print(f"Compilation failed: {e.message}")
    # Send to server
    packet_manager.compile_error_packet(e.message)
```

--------------------------------

### ConfigNode Constructor

Source: https://github.com/dmoj/judge-server/blob/master/_autodocs/api-reference/config.md

Constructor signature for ConfigNode.

```python
ConfigNode(
    raw_config: dict = None,
    parent: ConfigNode = None,
    defaults: dict = None,
    dynamic: bool = True
) -> None
```

--------------------------------

### Judge.update_problems Example

Source: https://github.com/dmoj/judge-server/blob/master/_autodocs/api-reference/judge.md

Pushes the current problem set to the judge server.

```python
judge = Judge(packet_manager)
judge.update_problems()
```

--------------------------------

### Server Mode Usage

Source: https://github.com/dmoj/judge-server/blob/master/_autodocs/configuration.md

Command-line usage for running the DMOJ judge in server mode, including positional arguments and available options.

```bash
dmoj [options] server_host [judge_name] [judge_key]
```

--------------------------------

### Docker Tier 1 Judge Image Setup and Run

Source: https://github.com/dmoj/judge-server/blob/master/README.md

Clones the judge-server repository, builds a tier 1 judge image, and runs it with specified configurations and environment variables.

```bash
$ git clone --recursive https://github.com/DMOJ/judge-server.git
$ cd judge-server/.docker
$ make judge-tier1
$ exec docker run \
    --name judge \
    -p "$(ip addr show dev enp1s0 | perl -ne 'm@inet (.*)/.*@ and print$1 and exit')":9998:9998 \
    -v /mnt/problems:/problems \
    --cap-add=SYS_PTRACE \
    -d \
    --restart=always \
    dmoj/judge-tier1:latest \
    run -p15001 -s -c /problems/judge.yml \
    "$BRIDGE_ADDRESS" "$JUDGE_NAME" "$JUDGE_KEY"
```