18 Sep 25
Rendezvous hashing is an algorithm to solve the distributed hash table problem - a common and general pattern in distributed systems.
19 Feb 25
Overview of Relaxed Radix Balanced Trees, a data structure that allows for efficient merging of Persistent Vectors.
03 Sep 22
An introduction to bitmaps, what they’re used for, and what Roaring bitmaps solve that traditional bitmaps don’t.
28 Jan 22
Python notebook detailing how to get the daily Wordle on the first try using the obfuscated replay results that are shared on twitter and other social media platforms.
02 Jan 22
Overview of how audio fingerprinting works.
19 Aug 21
High-level introduction to B-trees and why they are practical when implementing databases.
26 Mar 21
Author discusses how he accidentally wrote a parser with quadratic complexity.
04 Jan 21
Introduction to the technique (known as “dithering”) used for the graphics of the game: “Return of the Obra Dinn”.
08 Dec 20
This guide covers various ways to make hexagonal grids, the relationships between different approaches, and common formulas and algorithms. Most parts of this page are interactive.
27 Nov 20
Introduction to shuffle-sharding and how it’s used in AWS to deliver multi-tenant services that give each customer a single-tenant experience.
05 Oct 20
This article discusses a relatively unknown data structure, the suffix tree, and shows how its characteristics can be used to attack difficult string matching problems.
22 Sep 18
Article that describes the steps to generate the code in MS Excelwithout using any Visual Basic or other scripting.
30 Aug 17
Overview of several approaches to rank results by an average score provided by users, and why most fail to provide a satisfying solution. Concluding with a formula that yields better results.
10 Aug 16
Notes on how to programmatically generate fictional maps that look like something you’d find at the back of fantasy novels.
06 Mar 12
List of ingenious algorithms in computer science
19 Jan 12
Efficiently querying geospatial data is a considerable challenge: because the data is two-dimensional (or sometimes, more), you can’t use standard indexing techniques to query on position. Spatial indexes solve this through a variety of techniques. This post covers several - quadtrees, geohashes, and space-filling curves - and reveal how they’re all interrelated.
29 Nov 11
Introduction to Ternary Search Tries
Notes on the following algorithms and methods:
- Levenshtein distance
- Damerau-Levenshtein distance
- Bitap algorithm with modifications by Wu and Manber
- Spell-checker method
- N-gram method
- Signature hashing method
- BK-trees
02 Sep 11
Most people use this web site to get information about a particular number sequence. If you are a new visitor, then you might ask the database if it can recognize your favorite sequence, if you have one.
12 May 11
Encoding images under 140 characters.