matchings-in-biparite-graphs

matchings-in-biparite-graphs is a skill for Claude Code, Codex from Arcadi4/nerdy. It costs 55 tokens per session (4,740 once invoked), scanned A, original, MIT.

A guide to matching problems that pair items from two separate groups, including ordinary, preference-based, and weighted pairings.

In plain words
What is it for?
Bipartite matching, Hopcroft–Karp, stable marriage, Gale–Shapley, Hungarian assignment, and augmenting-path proofs.
Why use it?
It helps select the right model and proof: maximum size, stable preferences, or minimum-cost assignment each need different methods and certificates.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one.

Good fit Bipartite matching, Hopcroft–Karp, stable marriage, Gale–Shapley, Hungarian assignment, and augmenting-path proofs.

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Install with agentmods
npx agentmods add skills/arcadi4/nerdy/matchings-in-biparite-graphs
Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Any agent
npx skills add Arcadi4/nerdy --skill matchings-in-biparite-graphs
Clone the repo
git clone --depth 1 https://github.com/Arcadi4/nerdy

Made for: Claude Code, Codex.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for matchings-in-biparite-graphs

README.md
[![agentmods](https://agentmods.dev/badge/skills/arcadi4/nerdy/matchings-in-biparite-graphs/github.svg)](https://agentmods.dev/skills/arcadi4/nerdy/matchings-in-biparite-graphs)
Your own site
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Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for matchings-in-biparite-graphs

Your own site · 80×15
<a href="https://agentmods.dev/skills/arcadi4/nerdy/matchings-in-biparite-graphs"><img src="https://agentmods.dev/badge/skills/arcadi4/nerdy/matchings-in-biparite-graphs.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 55 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 4,740 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00055 $0.04740
Opus 5 $0.00028 $0.02370
Sonnet 5 $0.00011 $0.00948
Haiku 4.5 $0.00006 $0.00474

Measured 11d ago against content hash 824d9cd6fac4, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-11, from the pricing page.

Security

Grade A, and why

matchings-in-biparite-graphs scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 11d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

clrs/matchings-in-biparite-graphs/SKILL.md · 399 lines

How it starts

The opening of the file, as written. The whole thing — 399 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Matchings in Bipartite Graphs

Overview

Matching answers are dual-structure answers: first decide whether the task is cardinality matching, stable preference matching, or weighted assignment, then use the certificate that belongs to that model. Augmenting paths certify maximum cardinality, no blocking pair certifies stability, and feasible labels plus equality edges certify optimal weighted assignments.

Core principle: do not collapse the chapter into a generic max-flow reduction. Preserve the matching-specific alternating-path, rejection, and labeling proof moves, then translate textbook pseudocode into implementation contracts only when the input model justifies it.

Shared CLRS Conventions

  • Follow the parent clrs skill for mathematical formatting: every formula, inequality, set expression, slack definition, or asymptotic bound belongs in a display LaTeX block, never in prose, headings, table cells, or inline code spans.
  • Use elementary-graph-algorithms for ordinary graph representation, breadth-first search, depth-first search, and transpose traversal mechanics.
  • Use maximum-flow when the requested deliverable is a flow-network reduction or an integrality proof. Use this skill when the requested deliverable is a matching algorithm, matching theorem, stable-matching proof, or assignment-labeling argument.
  • Keep quick-reference tables verbal. Put all symbolic definitions and running times in display blocks near the table.
  • State which side of the bipartition proposes, which side is optimized, and whether the matching is cardinality, stable, or weighted before naming an algorithm.
  • Start directly with the polished answer. The first visible line must be a domain heading or a substantive matching sentence, not a process note. Do not include meta preambles such as “checking formatting,” “evaluating complexity,” “evaluating the skill,” “I’m thinking,” “displaying complexity,” “scenario answer,” or “finalizing the presentation,” because those are common places for forbidden inline formulas and session narration to leak. If a draft starts with one of those phrases, delete the preamble before answering.

Read the full file on GitHub · 399 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 11d ago First seen · 399 lines · 55 tokens per session scan A 824d9cd6fac4

Subscribe to this mod's changes

matchings-in-biparite-graphs is a skill published in the GitHub repository Arcadi4/nerdy (7 stars, last pushed 4mo ago), licensed MIT. It adds 55 tokens to every session and 4,740 once invoked, about $0.0003 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.