https://github.com/afnanenayet/hashed-permutation

An implementation of Kensler's hashed permutation algorithm
https://github.com/afnanenayet/hashed-permutation

hash hashed permutation permute shuffle

Last synced: 5 months ago
JSON representation

An implementation of Kensler's hashed permutation algorithm

• Host: GitHub
• URL: https://github.com/afnanenayet/hashed-permutation
• Owner: afnanenayet
• License: mit
• Created: 2019-09-09T03:53:39.000Z (about 6 years ago)
• Default Branch: main
• Last Pushed: 2025-01-31T17:57:16.000Z (9 months ago)
• Last Synced: 2025-04-26T07:52:59.907Z (6 months ago)
• Topics: hash, hashed, permutation, permute, shuffle
• Language: Rust
• Size: 71.3 KB
• Stars: 16
• Watchers: 2
• Forks: 3
• Open Issues: 7
• Metadata Files:
  • Readme: docs/README.md
  • License: LICENSE.txt

Awesome Lists containing this project

README

          
# hashed-permutation

[![CI](https://github.com/afnanenayet/hashed-permutation/actions/workflows/CI.yml/badge.svg)](https://github.com/afnanenayet/hashed-permutation/actions/workflows/CI.yml)

[![crates badge](https://meritbadge.herokuapp.com/hashed-permutation)](https://crates.io/crates/hashed-permutation)

[![Documentation](https://docs.rs/hashed-permutation/badge.svg)](https://docs.rs/hashed-permutation)

![License](https://img.shields.io/crates/l/hashed-permutation/1.0.0.svg)

## Synopsis

This is an implementation of Andrew Kensler's hashed permutation, which allows

you to take an array of the elements [0 ... n) and shuffle it with no memory

overhead and very little computational overhead. This works by using a clever

hash function to effectively permute all of the elements in the array.

Basically, you get a nearly free method to shuffle a bunch of numbers that

doesn't require you to allocate a vector of size `n`, letting you sample the

set without replacement.

You can find the paper here: https://graphics.pixar.com/library/MultiJitteredSampling/paper.pdf.

I have a little writeup of how the algorithm works [here](https://afnan.io/posts/2019-04-05-explaining-the-hashed-permutation),

and [Timothy Hobbs](https://github.com/timthelion) made a nice writeup explaining how to use the library itself

[here](https://timothy.hobbs.cz/rust-play/hashed-permutation.html).