Pattern Documentation Index¶

Auto-generated from: ontology/ + meta/patterns/
Generator: tools/generate_pattern_docs.py

This directory contains comprehensive documentation for each API Kernel and its associated problem-solving Patterns. Each document serves as a complete reference for understanding, implementing, and applying these patterns.

Available Pattern Guides¶

API Kernel	Document	Description	Problems
`SubstringSlidingWindow`	sliding_window.md	Dynamic window over sequences	LeetCode 3, 76, 159, 209, 340, 438, 567
`TwoPointersTraversal`	two_pointers.md	Two pointer traversal patterns	LeetCode 1, 11, 15, 16, 21, 26, 27, 75, 88, 125, 141, 142, 167, 202, 283, 680, 876
`GridBFSMultiSource`	coming soon	Multi-source BFS on grids	LeetCode 994, 286, 542
`BacktrackingExploration`	coming soon	Exhaustive search with pruning	LeetCode 51, 52, 46, 78
`KWayMerge`	coming soon	Merge K sorted sequences	LeetCode 23, 21, 88
`BinarySearchBoundary`	coming soon	Binary search boundaries	LeetCode 4, 33, 34, 35
`LinkedListInPlaceReversal`	coming soon	In-place linked list reversal	LeetCode 25, 206, 92
`MonotonicStack`	coming soon	Monotonic stack patterns	LeetCode 84, 85, 496

Document Structure¶

Each pattern document follows a consistent structure:

1. Header
   - API Kernel name and core mechanism
   - Overview of the pattern family

2. Core Concepts
   - Fundamental principles
   - Universal template structure
   - Strategy variants (maximize/minimize/fixed)

3. Base Template Problem
   - The "ancestor" problem that defines the pattern
   - Complete implementation with detailed comments
   - Algorithm explanation and trace examples

4. Variation Problems
   - Each variation shows:
     - Problem statement and invariant
     - Delta from base template (what changes)
     - Complete implementation
     - Key insights

5. Comparison Table
   - Side-by-side comparison of all variations

6. Decision Guide
   - When to use this pattern
   - Decision flowchart

7. Quick Reference Templates
   - Copy-paste ready templates

Source Files¶

Pattern documentation is composed from:

meta/
└── patterns/
    └── <api_kernel_id>/
        ├── _header.md        # Core concepts
        ├── _comparison.md    # Comparison table
        ├── _decision.md      # When to use
        ├── _templates.md     # Quick reference
        └── XXXX_<name>.md    # Per-problem snippets

Example: Sliding Window¶

meta/patterns/sliding_window/
├── _config.toml             # File ordering configuration (optional)
├── _header.md               # Invariant, template structure, strategies
├── _comparison.md           # Pattern comparison table
├── _decision.md             # When to use sliding window
├── _templates.md            # Maximize/minimize/fixed templates
├── 0003_base.md             # LeetCode 3 - Base template
├── 0076_min_window.md       # LeetCode 76 - Minimum Window Substring
├── 0209_min_subarray.md     # LeetCode 209 - Minimum Size Subarray Sum
├── 0340_k_distinct.md       # LeetCode 340 - At Most K Distinct
├── 0438_anagrams.md         # LeetCode 438 - Find All Anagrams
└── 0567_permutation.md      # LeetCode 567 - Permutation in String

File Ordering Configuration¶

Each pattern directory can include a _config.toml file to control the order of files in the final document:

# meta/patterns/<pattern_name>/_config.toml
header_files = ["_header.md"]
problem_files = ["0003_base.md", "0076_min_window.md", ...]
footer_files = ["_comparison.md", "_decision.md", "_templates.md"]

If _config.toml exists: Files are ordered exactly as specified
If _config.toml doesn't exist: Falls back to default ordering (alphabetical for problems)

See meta/patterns/README.md for detailed documentation.

Generating Documentation¶

To regenerate pattern documentation:

python tools/generate_pattern_docs.py

Options:

# Generate specific pattern
python tools/generate_pattern_docs.py --pattern sliding_window

# Generate all patterns
python tools/generate_pattern_docs.py --all

# Validate only (no write)
python tools/generate_pattern_docs.py --validate

Adding New Patterns¶

1. Define in Ontology¶

Add the API Kernel in ontology/api_kernels.toml:

[[api_kernels]]
id = "NewKernel"
summary = "Description of the kernel mechanism."

Add patterns in ontology/patterns.toml:

[[patterns]]
id = "new_pattern_variant"
api_kernel = "NewKernel"
summary = "Description of this specific pattern."

2. Create Source Files¶

Create directory and files in meta/patterns/:

meta/patterns/new_kernel/
├── _header.md
├── _comparison.md
├── _decision.md
├── _templates.md
└── XXXX_problem.md

3. Generate Documentation¶

python tools/generate_pattern_docs.py --pattern new_kernel

Relationship to Problem Metadata¶

Each problem in meta/problems/*.toml references patterns:

# meta/problems/0003_longest_substring_without_repeating_characters.toml
api_kernels = ["SubstringSlidingWindow"]
patterns    = ["sliding_window_unique"]

[pattern_role]
is_base_template = true
base_for_kernel  = "SubstringSlidingWindow"
derived_problems = ["0076", "0159", "0209", "0340", "0438", "0567"]

The generator uses this metadata to: - Order problems correctly (base first, then variations) - Generate cross-references - Build the comparison table automatically

Last updated: Auto-generated by tools/generate_pattern_docs.py