It’s cool to talk about cellular automata, everyone’s doing it. But how many people do it in reverse?

Here’s a simple PHP script to take any row of Rule 30 and wind it back to the initial state:

https://raw.githubusercontent.com/AlexanderParker/MyMillionNumberChallenge/master/attempts/23-automata/reverse-30.php

If you want to play in your browser, here’s a JavaScript version:

It was inspired by a page on the following link, which provided the conceptual approach which my solution is based on:

https://www.mathpages.com/home/kmath439/kmath439.htm

Anyway. No magic here, just a way to easily wind back iterations of Rule 30 if you want to.

Hopefully it’s clear enough how it works to transpose to other languages otherwise let me know and I can try and provide some translations.

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