211
The Halting Problem is a terrible example of NP-Harder
It's a justifiable copout, but it's still a copout.
Topics /
Math & Algorithms
The most popular blog posts about math & algorithms on Hacker News. 238 posts.
212
When would you ever want bubblesort? (2023)
There are very few universal rules in software engineering, but there are are a lot of near-universal principles. Things like "prefer composition to...
213
Introduction to Digital Filters (2024)
INTRODUCTION TO DIGITAL FILTERS WITH AUDIO APPLICATIONS
214
Parsing Advances
I find myself writing yet another toy parser, as one does during a Christmas break. It roughly follows Resilient LL Parsing Tutorial. Not because I need resilience, but mostly because I find producing a syntax tree and a collection of diagnostics a more natural fit for the problem than bailing out on the first error.
215
Monte Carlo Crash Course: Sampling
In the previous chapter, we assumed that we can uniformly randomly sample our domain. However, it’s not obvious how to actually do so—in fact, how can a deterministic computer even generate random numbers? 1
216
The exceptional Jordan algebra (2020)
In the early 1930s, Pascual Jordan attempted to formalise the algebraic properties of Hermitian matrices. In particular: Hermitian matrices form a real vector space: we can add and subtract Hermiti…
217
The Hat, the Spectre and SAT Solvers (2024)
Introduction In this blog post you are going to read about two things:
218
Numbering should start at zero (1982)
To denote the subsequence of natural numbers 2, 3, ..., 12 without the pernicious three dots, four conventions are open to us
219
The economics behind "Basic Economy" – A masterclass in price discrimination
Basic Economy fares are ultra-restricted airline tickets that offer a lower base price in exchange for fewer benefits than standard economy class. Introduced by major U.S. carriers in the 2010s, these fares have become a widespread strategy for market segmentation - a textbook example of price discrimination in…
220
Code golfing a tiny demo using maths and a pinch of insanity
The number of characters was 464 characters at first, but thanks to the community it got reduced further, and the article updated accordingly.
221
Lambda Calculus and Lisp, part 1
The first of a series of envisioned blog posts on lambda calculus, and Lisp. It’s unclear exactly where to start: there is a whole heap of interesting issues, both theoretical and in terms of concrete implementations, which tangle and interconnect. A particular application of lambda calculus is a very salient…
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Transducer: Composition, abstraction, performance (2018)
Transducer: Composition, Abstraction, Performance
224
Convolutions, Polynomials and Flipped Kernels
This is a post about multiplying polynomials, convolution sums and the connection between them.
225
Is Fortran better than Python for teaching basics of numerical linear algebra?
Quarto Academic Website Template adapted by Dr. Gang He
226
Analytic Combinatorics – A Worked Example
Chris Grossack's math blog and professional website.
227
Derivation and Intuition behind Poisson distribution
Made in Notion, the connected workspace where AI agents and teams organize docs, projects and knowledge together.
228
Using obscure graph theory to solve programming languages problems
Usually I write about solutions to problems I’ve worked out, but I’ve found myself increasingly becoming interesting in where solutions come from. Maybe it’s because I’ve been reading Boorstin’s excellent The Discoverers , which I’d strongly recommend.
229
Derivatives and Logarithms of 3D Transforms
Understanding derivatives and logarithms of transforms
230
Weighting an average to minimize variance
How would you allocate money to a set of independent assets with to minimize volatility if some assets are more volatile than others?
231
Fold-... and Monoids
A blog about computers, functional languages, Lisp, and Scheme.
232
Estimating Logarithms
While reading through the fantastic book *[The Lost Art of Logarithms](https://www.lostartoflogarithms.com/)* by [Charles Petzold](https://www.charlespetzold.com/) I was nerd-sniped by a [simple method](https://www.lostartoflogarithms.com/chapter04/) of estimating the logarithm of any number base 10. According to the…
233
Minimal Boolean Formulas (2011)
28 . That's the minimum number of AND or OR operators you need in order to write any Boolean function of five variables. Alex Healy and I computed that in April 2010. Until then, I believe no one had ever known that little fact. This post describes how we computed it and how we almost got scooped by Knuth's Volume 4A…
234
Entropy Attacks
The conventional wisdom is that hashing more entropy sources can't hurt: if H is any modern cryptographic hash function then H(x,y,z) is at least as good a random number as H(x,y), no matter how awful z is. So we pile one source on top of another, hashing them all together and hoping that at least one of them is good.
235
Collatz's Ant
This is a brief continuation of a previous post ( Repo ), which introduced such visualization for collatz sequences based on Langton’s Ant .
236
Solving LinkedIn Queens Using Haskell
Solving LinkedIn Queens in the LogicT monad
237
A cute proof that makes e natural
Po-Shen Loh explains why Euler's number e is natural using only precalculus: one exponential curve has tangent slope 1 at the y-axis, which leads to the compound interest limit.
238
Reflections on Sudoku, or the Impossibility of Systematizing Thought
I reflect on the Entscheidungsproblem how it relates to Sudoku solvers. It's a little weird. .