Problem Note Contract

This page is for contributors and maintainers, not first-time learners.

Use it when you are writing or revising a solved note under practice/ladders/.

Required Fields

• Title
• Judge / source
• Original URL
• Secondary topics
• Difficulty
• Status: todo, attempted, solved, reviewed
• Solution file

Derived Field

• Main topic: generated from the note path practice/ladders/<area>/<subtopic>/... and the canonical title in data/topic-resources.json

Optional Fields

• Subtype
• Mirror / English URL
• Source contest
• Alternate solution variants

Suggested Section Order

1. Why practice this
2. Recognition Cue
3. Problem-Specific Transformation
4. Core Idea
5. Complexity
6. Pitfalls / Judge Notes
7. Reusable Pattern
8. Solutions

Writing Rules

• solved notes should emphasize the delta from the topic page, not reteach the entire topic from scratch
• Recognition Cue should help the reader notice the right pattern next time
• Problem-Specific Transformation should explain how the raw statement was rewritten into that pattern
• Reusable Pattern should point back to the best internal topic, template, and notebook refreshers

Maintenance Check

When a note changes enough to affect catalogs or docs, rerun:

python3 scripts/generate_problem_catalog.py --validate-only
python3 scripts/generate_problem_catalog.py
python3 scripts/build_site_docs.py
mkdocs build --strict