advent-of-code/2021/src/bin/day21.rs
2021-12-21 21:57:53 +01:00

49 lines
1.1 KiB
Rust

#![feature(test)]
extern crate test;
type Parsed = (u16, u16);
const INPUT: Parsed = (7, 3);
fn part1((p1, p2): Parsed) -> usize {
(1..=100)
.cycle()
.skip(1)
.step_by(3)
.zip(1..)
.scan([(p2, 0), (p1, 0)], |mut scores, (die, round)| {
let mut points = scores[round & 1].0 + die * 3;
points -= (points - 1) / 10 * 10;
scores[round & 1].0 = points;
scores[round & 1].1 += points;
Some((round, (scores[0].1, scores[1].1)))
})
.find_map(|(r, (s1, s2))| (s1 >= 1000 || s2 >= 1000).then(|| r * 3 * (s1.min(s2) as usize)))
.unwrap()
}
fn part2((p1, p2): Parsed) -> usize {
unimplemented!()
}
fn main() {
println!("Part 1: {}", part1(INPUT));
println!("Part 2: {}", part2(INPUT));
}
#[cfg(test)]
mod tests {
use super::*;
use aoc2021::*;
#[test]
fn part1_test() {
assert_eq!(part1((4, 8)), 739785);
}
#[bench]
fn part1_bench(b: &mut test::Bencher) {
b.iter(|| assert_eq!(part1(test::black_box(INPUT)), 551901))
}
}