Templates

The power of rbxTeX comes from its template system. The content you write in blocks (description, input, output) is injected into a base LaTeX template to produce the final document.

Default template

By default, rbx uses a built-in template that provides a standard competitive programming layout. However, you can (and often should) provide your own template.rbx.tex or modify the existing template to match your contest's branding or specific requirements.

To use the default template as is, you can simply create a problem from the default preset, and fill in the blocks in your main statement file.

You can find the default template here to use as inspiration to create your own.

Customizing templates

To use a custom template, simply create a file named template.rbx.tex in the same directory as your statement file, and refer to it in your statement configuration.

problem.rbx.yml

statements:
  - name: statement
    path: statement/statement.rbx.tex
    configure:
      - type: rbx-tex
        template: "statement/template.rbx.tex"

Template structure

A template is a LaTeX file that defines the document structure and placeholders for content blocks. It uses Jinja2 syntax for logic and variables.

rbx-provided variables

The following variables are available in the template context:

• problem: An object containing problem metadata.
  • problem.title: The problem title.
  • problem.short_name: The problem short name (e.g., A, B, etc.).
  • problem.blocks: A dictionary of content blocks (e.g., problem.blocks.legend, problem.blocks.input, etc.).
  • problem.samples: A list of sample objects.
  • problem.vars: Variables defined in problem.rbx.yml.
  • problem.limits: Time and memory limits.

The sample object contains the following attributes:

• sample.inputPath: The input path, relative to the statement build directory (a pathlib.Path object, so read_text() can be called)
• sample.outputPath: The output path, relative to the statement build directory, similar to the input path

The limits object contains the following attributes/methods:

• limits.timeLimit: The time limit in milliseconds
• limits.memoryLimit: The memory limit in megabytes
• limits.outputLimit: The output limit in megabytes
• limits.timelimit_for_language(lang): The time limit in milliseconds for a specific language.
• limits.memorylimit_for_language(lang): The memory limit in megabytes for a specific language.

Creating custom blocks

While the default template uses standard blocks (description, input, etc.), you can define custom blocks in your rbxTeX files and render them in your template.

For example, if you want a "Hint" section:

1. In your statement:

   statement.rbx.tex

   %- block hint
   Try to use dynamic programming.
   %- endblock
   

2. In your template:

   template.rbx.tex

   % ...
   %- if problem.blocks.hint
   \section*{Hint}
   \VAR{problem.blocks.hint}
   %- endif
   % ...
   

This gives you unlimited flexibility to structure your problem statements.

Example Template

Here is a simplified example of a custom template:

template.rbx.tex

\documentclass{article}
\begin{document}

\section*{\VAR{problem.short_name}. \VAR{problem.title}}

\VAR{problem.blocks.description}

\subsection*{Input}
\VAR{problem.blocks.input}

\subsection*{Output}
\VAR{problem.blocks.output}

\subsection*{Samples}
%- for sample in problem.samples
\subsection*{Sample \VAR{loop.index}}
\begin{itemize}
    \item \textbf{Input:} \texttt{\VAR{sample.inputPath.read_text()}}
    \item \textbf{Output:} \texttt{\VAR{sample.outputPath.read_text()}}
\end{itemize}
%- endfor

%- if problem.blocks.notes is defined
\subsection*{Note}
\VAR{problem.blocks.notes}
%- endif

\end{document}

Learn more through examples

Look at our default preset to see how it works and modify it to your liking.