Data Structures & Algorithms · Ch 5
Hashing
Why a hash map lookup is one jump, when it stops being one, separate chaining, open addressing with tombstones, resizing, and the inputs that break it. Every code block runs.
Agent skillClaude Code pluginMIT
Course Studio
Plan and write courses, chapters, notes and cheat sheets on anything, from binary search to how a rocket engine works. Every diagram is an interactive isometric machine whose working is the idea, and every page is built and checked before you see it.
$ npx skills add akshaypjoshi/course-studio -g -a claude-code
/plugin marketplace add akshaypjoshi/course-studio /plugin install course-studio@course-studio
Live figure
Figures you can play with, not boxes and arrows
This is the figure from the demo chapter on hashing, running live. A dial computes k mod 8 and a shuttle drops each key into its tray. Hover or use the arrow keys to step through inserts, and watch one bad set of keys pile into a single chain.
Built by the bundled Anatomy engine from one
build.mjsSee it in the chapterNot just software
How a SpaceX rocket works? Draw the real engine.
For a physical subject the figure is the thing itself. This is the figure from the second demo chapter, Inside the engine: Raptor 2, SpaceX's full-flow staged-combustion engine, on a test stand. Hover or use the arrow keys to take it apart part by part, then press Ignite and watch the preburners light before the chamber reaches 300 bar.
Numbers from SpaceX's published figures, shared with the chapter through one model fileSee it in the chapter
What you ask for
Just name the topic
The skill picks the scope from your request, says it in one line, and gets to work in ./courses/.
"Plan a System Design course"
A course plan
Outcomes, prerequisites and chapters in dependency order, each with one planned figure. Built into a syllabus page and a catalog.
"Write the binary search chapter"
A full chapter
A fixed teaching arc from hook to recap, code that has been run, its signature figure, and a built page.
"Notes on consistent hashing"
Notes and interview prep
A compressed arc: idea, mechanism, code, pitfalls, two checks. Reuses a chapter figure where one fits.
"Cheat sheet for graphs"
A cheat sheet
Tables, patterns, complexity grids and one-liners on one or two screens. No new figures, links for depth.
"A course on how rockets work"
Any subject
Machines, the body, physics, markets. Real things drawn as themselves, numbers taken from published sources.
"Lesson on how the heart pumps"
Any audience
From school students to professionals. The writing adapts; the checks stay the same.
How it works
Text and figure share one source of truth
The figure is driven by the same model as the chapter's worked example, so the numbers on the card are the numbers in the text.
Outline
One outcome sentence per section, then the single insight that most needs to be seen moving.
Brief the figure
The idea, the truth model with the chapter's exact numbers, a physical object from an atlas of about 90 concepts, and the tour beats.
Build it
The Anatomy engine draws a detailed isometric machine with a live readout, then audits it for painter's order and clipping.
Write and check
The chapter is written around the figure, every code block is run, and the page is checked on desktop, phone and dark mode.
Quality bar
Checked, not just generated
- Every code block is run, every number verified, and real-world facts taken from published sources, not memory.
- Pages pass a headless check: no JS errors, clipped or missing figures, broken links or sideways scroll.
- Figures pass their own audit and are reviewed at 4x, on a 390px phone and in both themes.
- One house style: dense prose, no filler, no em dashes. Builds warn and checks catch anything that slips.
- Markdown is the source, with GitHub-style callouts and a one-line
::figuredirective for your own platform. - Pages are self-contained HTML with figures embedded, in light and dark.
Demos
Read two finished chapters
Both bundled examples, written and checked with the skill, and rebuilt by its own scripts on every deploy. One is an algorithms course, the other a course on rockets for curious adults.
How Rockets Work · Ch 3
Inside the engine
Why a rocket engine is a pump problem, and how SpaceX's Raptor drives its pumps with the propellants they pump. Real numbers with dates and sources, checked with back-of-envelope arithmetic.
Requirements
One install, a few local tools
The Anatomy figure engine is bundled, so the skill is all you add. Building pages and figures uses tools you likely have.
| Tool | Needed for |
|---|---|
Python 3.9+ with markdown, pyyaml, pygments | Building pages (pip install -r requirements.txt in the skill folder) |
playwright and Chromium | The headless page check |
| Node.js 20.10+ | Building figures. Without it the skill still writes; figures wait as briefs. |