aoc2022/src/day2.rs

pub mod a {
	static INPUT: &str = include_str!("inputs/day2a.txt");

	#[derive(Copy, Clone, Eq, PartialEq)]
	pub enum Rps {
		Rock,
		Paper,
		Scissors,
	}
	impl Rps {
		pub fn score(&self) -> u64 {
			use Rps::*;

			match self {
				Rock => 1,
				Paper => 2,
				Scissors => 3,
			}
		}
	}

	pub enum Outcome {
		ElfWin,
		MeWin,
		Draw,
	}
	impl Outcome {
		pub fn score(&self) -> u64 {
			use Outcome::*;

			match self {
				ElfWin => 0,
				Draw => 3,
				MeWin => 6,
			}
		}
	}

	pub fn get_outcome(elf: &Rps, me: &Rps) -> Outcome {
		use Rps::*;

		match (elf, me) {
			(Paper, Rock) | (Rock, Scissors) | (Scissors, Paper) => {
				Outcome::ElfWin
			}
			_ if elf == me => Outcome::Draw,
			_ => Outcome::MeWin,
		}
	}

	pub fn elf_to_rps(i: &str) -> Rps {
		match i {
			"A" => Rps::Rock,
			"B" => Rps::Paper,
			"C" => Rps::Scissors,
			_ => panic!(),
		}
	}

	pub fn me_to_rps(i: &str) -> Rps {
		match i {
			"X" => Rps::Rock,
			"Y" => Rps::Paper,
			"Z" => Rps::Scissors,
			_ => panic!(),
		}
	}

	pub fn go() {
		let input = INPUT;
		let score = input
			.split('\n')
			.filter(|line| !line.is_empty())
			.map(|line| {
				let mut it = line.split(' ');
				let elf = it.next().unwrap();
				let me = it.next().unwrap();

				let elf = elf_to_rps(elf);
				let me = me_to_rps(me);

				let me_score = me.score() + get_outcome(&elf, &me).score();

				me_score
			})
			.sum::<u64>();

		println!("{}", score);
	}
}

pub mod b {
	use super::a::*;

	static INPUT: &str = include_str!("inputs/day2a.txt");

	fn to_outcome(me: &str) -> Outcome {
		use Outcome::*;
		match me {
			"X" => ElfWin,
			"Y" => Draw,
			"Z" => MeWin,
			_ => panic!(),
		}
	}

	fn get_move(elf: &Rps, outcome: &Outcome) -> Rps {
		use Outcome::*;
		use Rps::*;

		match outcome {
			Draw => *elf,
			ElfWin => match elf {
				Rock => Scissors,
				Scissors => Paper,
				Paper => Rock,
			},
			MeWin => match elf {
				Rock => Paper,
				Paper => Scissors,
				Scissors => Rock,
			},
		}
	}

	pub fn go() {
		let input = INPUT;
		let score = input
			.split('\n')
			.filter(|line| !line.is_empty())
			.map(|line| {
				let mut it = line.split(' ');
				let elf = it.next().unwrap();
				let outcome = it.next().unwrap();

				let elf = super::a::elf_to_rps(elf);
				let outcome = to_outcome(outcome);
				let me = get_move(&elf, &outcome);

				let me_score = me.score() + outcome.score();

				me_score
			})
			.sum::<u64>();

		println!("{}", score);
	}
}