# CodeViz

> Free, privacy-first online Python compiler and visual debugger. Write or paste
> Python, press Run, and step through execution watching variables, arrays,
> recursion trees, call stacks, and dynamic-programming tables. Built for students
> learning algorithms. No sign-up; submitted code is never stored or logged.

## Key pages
- [CodeViz app](https://codeviz.me/): the interactive Python visualizer
- [Algorithms, visualized](https://codeviz.me/algs/index.html): the 48 core algorithms from Princeton's Algorithms Part I and Part II (union-find, sorting, priority queues, BSTs, red-black trees, hashing, graphs, MST, shortest paths, max-flow, radix sorts, tries, substring search, compression). Each has runnable Python, a step-by-step animation generated from your own input, and the invariant that makes it correct.
  - Every algorithm also has its own page: `https://codeviz.me/algs/<id>.html` (e.g. `/algs/dijkstra.html`, `/algs/quicksort.html`, `/algs/kmp.html`) carrying the Python, the complexity table and the full explanation as static HTML. Those are the canonical documents; the interactive player is the same content at `/algs/index.html#a=<id>`. Enumerate them from https://codeviz.me/sitemap.xml or the Algorithms section of https://codeviz.me/sitemap.html.
  - Each of those pages has an "Open in Visualizer" link that carries the algorithm's code plus a ready-to-run test case into the main visualizer, so a reader can trace it on their own input.
- [All problems](https://codeviz.me/sitemap.html): index of the 54 built-in problems, grouped as Classroom (algorithms in course order) and Interview (by pattern)
- [Sitemap](https://codeviz.me/sitemap.xml): crawlable URLs

## Linking to one problem
Individual problems load via a URL fragment on the root page: `https://codeviz.me/#x=<id>`
(e.g. `#x=two_sum`, `#x=dijkstra`). Fragments are not separate documents - the root page
is canonical - so use https://codeviz.me/sitemap.html to enumerate the ids and titles.

## Notes
- Interactive, JavaScript-required single-page app; the step-by-step visualization is the core feature.
- Privacy: user code stays in the browser and is not persisted or logged server-side.