Best of 2025

The blog posts Hacker News loved most in 2025. 6,220 posts.

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3514

Relaxed Radix Balanced Trees (2024)

I’m adding immutable vectors to my language, Ivan, and needed to pick a suitable data structure to implement them. Clojure uses Persistent Vectors (PVs) which support lookups, updates, and appends all in ‘effectively’ constant time. However, it doesn’t have efficient insert or merge operations. Relaxed Radix Balanced…

3516

Memory access is O(N^[1/3])

In computer science, we often compare the efficiency of algorithms by describing their runtime as a function of the size of the input. Sorting is O(n * log(n)), meaning that sorting a list of N items takes an amount of time proportional to the number of items multiplied by its logarithm. Matrix multiplication is…

3526

Portals and Quake

Ever wanted to know how exactly did Quake’s precomputed visibility work? I did, so I wrote vis.py , a reimplementation of their algorithm in Python. This guide has all the information you need to understand vis , the tool used by Quake, Half-Life and Source Engine games.

3535

Bye, Prime

Why? · As I wrote in Not an Amazon Problem (and please go read that if you haven’t) I don’t see myself as an enemy of Amazon, particularly. I think the pressures of 21st-century capitalism have put every large company into a place where they really can’t afford to be ethical or the financial sector will rip them to…