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Start all of your commands with a comma (2009)

https://rhodesmill.org/brandon/2009/commands-with-comma/
250•theblazehen•2d ago•83 comments

Hoot: Scheme on WebAssembly

https://www.spritely.institute/hoot/
22•AlexeyBrin•1h ago•1 comments

OpenCiv3: Open-source, cross-platform reimagining of Civilization III

https://openciv3.org/
705•klaussilveira•15h ago•206 comments

The Waymo World Model

https://waymo.com/blog/2026/02/the-waymo-world-model-a-new-frontier-for-autonomous-driving-simula...
967•xnx•21h ago•558 comments

Vocal Guide – belt sing without killing yourself

https://jesperordrup.github.io/vocal-guide/
66•jesperordrup•5h ago•28 comments

Reinforcement Learning from Human Feedback

https://arxiv.org/abs/2504.12501
7•onurkanbkrc•42m ago•0 comments

Making geo joins faster with H3 indexes

https://floedb.ai/blog/how-we-made-geo-joins-400-faster-with-h3-indexes
135•matheusalmeida•2d ago•35 comments

Where did all the starships go?

https://www.datawrapper.de/blog/science-fiction-decline
42•speckx•4d ago•34 comments

Unseen Footage of Atari Battlezone Arcade Cabinet Production

https://arcadeblogger.com/2026/02/02/unseen-footage-of-atari-battlezone-cabinet-production/
68•videotopia•4d ago•6 comments

ga68, the GNU Algol 68 Compiler – FOSDEM 2026 [video]

https://fosdem.org/2026/schedule/event/PEXRTN-ga68-intro/
13•matt_d•3d ago•2 comments

Jeffrey Snover: "Welcome to the Room"

https://www.jsnover.com/blog/2026/02/01/welcome-to-the-room/
39•kaonwarb•3d ago•30 comments

What Is Ruliology?

https://writings.stephenwolfram.com/2026/01/what-is-ruliology/
45•helloplanets•4d ago•46 comments

Show HN: Look Ma, No Linux: Shell, App Installer, Vi, Cc on ESP32-S3 / BreezyBox

https://github.com/valdanylchuk/breezydemo
237•isitcontent•16h ago•26 comments

Monty: A minimal, secure Python interpreter written in Rust for use by AI

https://github.com/pydantic/monty
237•dmpetrov•16h ago•126 comments

Show HN: I spent 4 years building a UI design tool with only the features I use

https://vecti.com
340•vecti•18h ago•147 comments

Hackers (1995) Animated Experience

https://hackers-1995.vercel.app/
506•todsacerdoti•23h ago•247 comments

Sheldon Brown's Bicycle Technical Info

https://www.sheldonbrown.com/
389•ostacke•21h ago•97 comments

Show HN: If you lose your memory, how to regain access to your computer?

https://eljojo.github.io/rememory/
303•eljojo•18h ago•188 comments

Microsoft open-sources LiteBox, a security-focused library OS

https://github.com/microsoft/litebox
361•aktau•22h ago•186 comments

Cross-Region MSK Replication: K2K vs. MirrorMaker2

https://medium.com/lensesio/cross-region-msk-replication-a-comprehensive-performance-comparison-o...
3•andmarios•4d ago•1 comments

An Update on Heroku

https://www.heroku.com/blog/an-update-on-heroku/
428•lstoll•22h ago•284 comments

PC Floppy Copy Protection: Vault Prolok

https://martypc.blogspot.com/2024/09/pc-floppy-copy-protection-vault-prolok.html
71•kmm•5d ago•10 comments

The AI boom is causing shortages everywhere else

https://www.washingtonpost.com/technology/2026/02/07/ai-spending-economy-shortages/
25•1vuio0pswjnm7•2h ago•14 comments

Was Benoit Mandelbrot a hedgehog or a fox?

https://arxiv.org/abs/2602.01122
23•bikenaga•3d ago•11 comments

Dark Alley Mathematics

https://blog.szczepan.org/blog/three-points/
96•quibono•4d ago•22 comments

How to effectively write quality code with AI

https://heidenstedt.org/posts/2026/how-to-effectively-write-quality-code-with-ai/
270•i5heu•18h ago•219 comments

Delimited Continuations vs. Lwt for Threads

https://mirageos.org/blog/delimcc-vs-lwt
34•romes•4d ago•3 comments

I now assume that all ads on Apple news are scams

https://kirkville.com/i-now-assume-that-all-ads-on-apple-news-are-scams/
1079•cdrnsf•1d ago•461 comments

Introducing the Developer Knowledge API and MCP Server

https://developers.googleblog.com/introducing-the-developer-knowledge-api-and-mcp-server/
64•gfortaine•13h ago•30 comments

Understanding Neural Network, Visually

https://visualrambling.space/neural-network/
305•surprisetalk•3d ago•44 comments
Open in hackernews

How many paths of length K are there between A and B? (2021)

https://horace.io/walks
34•jxmorris12•5mo ago

Comments

Chinjut•5mo ago
Odd to use Berlelamp-Massey to recover a linear recurrence, when Cayley-Hamilton already directly gives you a linear recurrence whose characteristic polynomial is that of the matrix.
efavdb•5mo ago
But to get the polynomial you need to take the determine of A -lambda I, which runs in n^3. Next question then why doesn’t this Berlelamp-Massey method then effectively give you determinants in n^2?
shiandow•5mo ago
I think it could generate the minimal polynomiale instead. Though it is curious that this would still make it faster for almost all matrices, just not guaranteed to be correct.
Chinjut•5mo ago
Note that the article describes this Berlekamp-Massey approach as involving a step of complexity on the order of EV, which is V^3 in the worst-case. So this is only beneficial for sparse matrices. It does seem like Berlekamp-Massey is used to efficiently but non-guaranteedly compute determinants for sparse matrices, as described at https://en.wikipedia.org/wiki/Block_Wiedemann_algorithm
Labo333•5mo ago
CH gives you recurrence on the matrix. You want recurrence on an individual element (indexed by [start][end]).
Chinjut•5mo ago
Any recurrence that holds on the matrix also holds on each individual element (and vice versa, in that a recurrence holds on the matrix just in case it holds on every individual element).
gcanyon•5mo ago
I'm not sure what to make of the fact that for the abstract matrix problem in the original post, I thought about it for a moment without making any progress, but then for the knights on the phone pad problem it took me just two moments (about twenty seconds) to come up with the third solution -- and for context, I'm a product manager with a history as a developer. It would take me less than five minutes to code it up.

I wish I hadn't read the fourth solution description -- the language used wasn't clear at all to me, but it was enough to point me in the right direction, or maybe I'm just that clever?

That said, I don't like interview questions like that -- there's very much a component of you either get it or you don't. The interviewer says they talk people through it, and if they're good at that, great. But if not, a question like that is (in my book) unfair.

stephenlf•5mo ago
I am struggling to understand some of the explanations offered here. It’s certainly a skill issue on my part. I never learned DP in school and tabular DP has never clicked for me. However, I think there are a few things you could clarify.

> queue = [(A, 0)] # We track (length of walk, current node)

Surely the comment should be reversed, right?

Also, how are we encoding “current node”? Is it an integer? Does A=0, and the rest of the nodes have some arbitrary value? How do we calculate `neighbors(node)`?

quibono•5mo ago
Yes, the comment has it backwards.

> Also, how are we encoding “current node”? Is it an integer? Does A=0, and the rest of the nodes have some arbitrary value? How do we calculate `neighbors(node)`?

This is the "discussion" part of the interview where you're supposed to ask, and the interviewer will tell you that you can assume the nodes are numbered from 0/1 to N-1/N. I imagine the adjacency modeling is up to you since you'll be judged based off what representation you pick, and that will depend on the proposed solution.

stephenlf•5mo ago
I slept on the problem and, much like another commenter, found immense clarity by reading the actual interview question. The question is about knights on a phone pad. This article immediately starts with a generalization of the “knights on a phone pad” problem.
kazinator•5mo ago
> To avoid dealing with very large numbers, assume that we're computing our answer modulo a large prime.

Or tool up and get a better programming language?

xigoi•5mo ago
This is not about the programming language. Arbitrary-size integers make complexity analysis much more nuanced because arithmetic operations are no longer constant time.