Statements

The statement is the document that describes the problem to the contestant. It typically contains the problem description, input format, output format, constraints, and samples.

rbx supports a powerful and flexible statement system that allows you to write statements in multiple formats, including the custom rbxTeX format, as well as standard LaTeX and PDF.

Overview

Regardless of the format you choose, every statement goes through a build pipeline to generally produce a PDF file (though you can also export the intermediate LaTeX if needed).

graph LR
    Source[Source File] -->|Builder| TeX[LaTeX File]
    TeX -->|pdfLaTeX| PDF[PDF File]

Supported formats

rbx supports multiple formats for writing statements. We highly recommend using rbxTeX for most problems, as it offers the best balance between power and ease of use.

Format	Description	Best for...
rbxTeX	Recommended. A superset of LaTeX with block structure and variable interpolation.	Most problems. It separates content from layout effectively.
JinjaTeX	Pure LaTeX with Jinja2 templating.	Import existing statements, but still leverage from templating.
Pure LaTeX	Standard static LaTeX files.	Importing existing statements without modifications.
PDF	Pre-built PDF files.	Using statements that are already built/provided as PDFs.

Configuration

Statements are configured in the problem.rbx.yml file under the statements list. You can define multiple statements for the same problem (e.g., different languages, different versions).

problem.rbx.yml

statements:
  - name: statement-en        # (1)!
    language: en              # (2)!
    path: statement.en.tex    # (3)!
    type: rbx-tex             # (4)!
    assets:                   # (5)!
      - images/*.png
    vars:                     # (6)!
      editorial: false
      showLimits: true

1. name: A unique identifier for the statement. Used to refer to this statement.
2. language: The language code (ISO 639-1) for the statement.
3. path: Path to the statement file, relative to the package root.
4. type: The format of the statement. Can be rbx-tex, jinja-tex, tex, or pdf.
5. assets: A list of files (globs supported) to be included in the build directory.
6. vars: Custom variables to be injected into the statement.

Assets and resources

You can include images, style files, and other resources in your statement using the assets field. These files will be copied to the build directory alongside your statement file, preserving their relative paths.

statements:
  - name: statement-en
    path: statements/en.tex
    assets:
      - statements/images/*.png
      - statements/icpc.sty

In the case above, the statement source file en.tex will be placed in <build-dir>/en.tex while building, while an image such as statements/images/example.png will be placed in <build-dir>/images/example.png. In other words, the path of the asset relative to the statement source file is preserved in the build directory.

Tip

Keep your statement files and assets organized in a subdirectory (e.g., statements/ or doc/) to avoid cluttering the package root.

Building statements

To build statements, use the rbx statements build command (or alias rbx st b):

# Build all statements
rbx statements build

# Build specific statements by name
rbx statements build statement-en

# Build for specific languages
rbx statements build --languages en pt

The built statements will be placed in the build/ directory of your package.