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The most popular blog posts about math & algorithms on Hacker News. 75 posts.
To write a program to check if an integer is a power of two, you could follow two basic strategies: check the number based on its decimal value, or check it based on its binary representation. The former approach is more human-friendly but generally less efficient; the latter approach is more machine-friendly but…
Though it contains forms only for function applications, variable references and anonymous functions, it is equivalent to a Turing machine.
Skip lists are a fascinating data structure: very simple, and yet have the same asymptotic efficiency as much more complicated AVL trees and red-black trees.
There are two kinds of latitude: geocentric and astronomical. On a perfect sphere, they're the same, but on an oblate spheroid like Earth they're different.
Over break I went out with a buddy of mine and played some darts. This got me to thinking, where exactly should someone aim in order t...
This is the final article in my three-part look at symmetry reduction algorithms for speeding up pathfinding on uniform-cost grid maps. Recapping the story so far: Part one introduces the notion of…
I'm no graphics expert, but appreciate why square roots are useful. The Pythagorean theorem computes distance between points, and dividing by distance helps…
A crit-bit tree can be used as a high-speed associative array. For example, an array mapping 54 to 1, 19 to 2, 99 to 3, 85 to 4, and 88 to 5 can be stored as a crit-bit tree containing 54=1, 19=2, 99=3, 85=4, and 88=5. The smallest string in the crit-bit tree larger than 85= is 85=4.
Intro Fuzzy search algorithms (also known as similarity search algorithms) are a basis of spell-checkers and full-fledged search engines lik...
<img src="http://stevehanov.ca/wavelet/cup.png"/> Let's say you have millions of pictures of faces tagged with names. Given a new photo, how do you find the name of person that the photo most resembles? <p> In the cases I mentioned, each record has hundreds or thousands of elements: the pixels in a photo, or patterns…
Algorithms, circle mazes, hex grids, masking, weaving, braiding, 3D and 4D grids, spheres, and more!
Algorithms, circle mazes, hex grids, masking, weaving, braiding, 3D and 4D grids, spheres, and more!
