sorting-and-order-statistics

sorting-and-order-statistics is a skill for Claude Code, Codex from Arcadi4/nerdy. It costs 49 tokens per session (2,913 once invoked), scanned A, original, MIT.

An algorithm guide for putting data in order or selecting particular ranks, such as the median, a percentile, or the largest few items.

In plain words
What is it for?
Use it for sorting records, heaps, priority queues, quicksort, counting or radix sort, medians, quantiles, top-k results, and order statistics.
Why use it?
It helps choose a method based on the required ordering, key type, stability, memory use, and practical data layout.

Skill for Claude CodeCodex

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

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.

agentmods
npx agentmods add skills/arcadi4/nerdy/sorting-and-order-statistics
Any agent
npx skills add Arcadi4/nerdy --skill sorting-and-order-statistics
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 sorting-and-order-statistics

README.md
[![agentmods](https://agentmods.dev/badge/skills/arcadi4/nerdy/sorting-and-order-statistics.svg)](https://agentmods.dev/skills/arcadi4/nerdy/sorting-and-order-statistics)
Your own site
<a href="https://agentmods.dev/skills/arcadi4/nerdy/sorting-and-order-statistics"><img src="https://agentmods.dev/badge/skills/arcadi4/nerdy/sorting-and-order-statistics.svg" alt="Measured on agentmods" height="20"></a>
Per session 49 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 2,913 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
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 $0.00049 $0.02913
Opus 5 $0.00024 $0.01456
Sonnet 5 $0.00010 $0.00583
Haiku 4.5 $0.00005 $0.00291

Measured 6d ago against content hash a27805efdb44, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-06, from the pricing page.

Security

Grade A, and why

sorting-and-order-statistics 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 6d 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/sorting-and-order-statistics/SKILL.md · 185 lines

How it starts

The opening of the file, as written. The whole thing — 185 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Sorting and Order Statistics

Overview

Use sorting and selection as engineering tools, not reflexes. The core move is to identify the exact order information required, then choose the weakest ordering primitive that satisfies it under the real key, stability, memory, and adversary constraints.

Shared CLRS Conventions

Follow the parent clrs skill for mathematical formatting, formula-free headings, direct polished answers, and CLRS-wide answer style.

When to Use

  • You need to sort records, select a percentile, maintain top-k, merge sorted streams, or implement a priority queue.
  • A prompt involves heaps, heapsort, quicksort, counting sort, radix sort, bucket sort, medians, quantiles, or ith order statistics.
  • A comparison-sort lower bound seems relevant, or a proposed linear-time sort depends on integer keys, digits, or distribution assumptions.
  • An implementation must preserve satellite data, stability, handles, index maps, or large-payload locality.

Do not use this skill merely because output should appear sorted in a UI. Use the platform's ordinary sort unless algorithm choice, asymptotics, stability, or data-structure behavior matters.

First Decision: How Much Order Do You Need?

Need Prefer Why
General ordered records Library sort, stable sort if ties matter Production sorts are engineered for cache, duplicates, depth limits, and language semantics
Stable order by small dense integer key Counting sort or radix sort Beats comparison sorting only because key values can index counts or digits
Dynamic repeated min/max Binary heap priority queue Maintains partial order, not full sorted order
Merge k sorted streams Min-heap of stream heads Gives total cost based on k, not total stream count as a sort key
Single rank, median, percentile threshold Selection or nth_element Full sorting pays for order you will discard
Top-k unsorted Size-k heap or selection threshold Choose by k size, streaming needs, and memory
Top-k sorted Select threshold, partition top-k, then sort only k Avoids sorting the cold majority
Worst-case linear rank guarantee Median-of-medians SELECT Usually a fallback or proof tool because constants are high

Read the full file on GitHub · 185 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. 6d ago First seen · 185 lines · 49 tokens per session scan A a27805efdb44

Subscribe to this mod's changes

sorting-and-order-statistics is a skill published in the GitHub repository Arcadi4/nerdy (7 stars, last pushed 4mo ago), licensed MIT. It adds 49 tokens to every session and 2,913 once invoked, about $0.0002 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.

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