Module advent_solutions::advent2017::day25

Day 25: The Halting Problem

Following the twisty passageways deeper and deeper into the CPU, you finally reach the core of the computer. Here, in the expansive central chamber, you find a grand apparatus that fills the entire room, suspended nanometers above your head.

You had always imagined CPUs to be noisy, chaotic places, bustling with activity. Instead, the room is quiet, motionless, and dark.

Suddenly, you and the CPU's garbage collector startle each other. "It's not often we get many visitors here!", he says. You inquire about the stopped machinery.

"It stopped milliseconds ago; not sure why. I'm a garbage collector, not a doctor." You ask what the machine is for.

"Programs these days, don't know their origins. That's the Turing machine! It's what makes the whole computer work." You try to explain that Turing machines are merely models of computation, but he cuts you off. "No, see, that's just what they want you to think. Ultimately, inside every CPU, there's a Turing machine driving the whole thing! Too bad this one's broken. We're doomed!"

You ask how you can help. "Well, unfortunately, the only way to get the computer running again would be to create a whole new Turing machine from scratch, but there's no way you can-" He notices the look on your face, gives you a curious glance, shrugs, and goes back to sweeping the floor.

Structs

Blueprint	You find the Turing machine blueprints (your puzzle input) on a tablet in a nearby pile of debris. Looking back up at the broken Turing machine above, you can start to identify its parts:
State

Functions

parse_input
part1	For example, suppose you found the following blueprint:
part2	The Turing machine, and soon the entire computer, springs back to life. A console glows dimly nearby, awaiting your command.