85 lines
1.8 KiB
Rust
85 lines
1.8 KiB
Rust
#![feature(bool_to_option)]
|
|
#![feature(test)]
|
|
extern crate test;
|
|
use aoc2021::{
|
|
common::*,
|
|
grid::{Grid, PositionND},
|
|
};
|
|
|
|
const DAY: usize = 11;
|
|
const ROUNDS: usize = 100;
|
|
type Parsed = Grid<u8, 2>;
|
|
|
|
fn parse_input(raw: &str) -> Parsed {
|
|
Grid::<u8, 2>::from_bytes_2d(raw, |b: u8| b - b'0')
|
|
}
|
|
|
|
fn part1(parsed: &Parsed) -> usize {
|
|
let mut grid = parsed.to_owned();
|
|
(0..ROUNDS).map(|_| make_step(&mut grid)).sum()
|
|
}
|
|
|
|
fn part2(parsed: &Parsed) -> usize {
|
|
let mut grid = parsed.to_owned();
|
|
(0..).position(|_| make_step(&mut grid) == parsed.len()).unwrap() + 1
|
|
}
|
|
|
|
fn make_step(grid: &mut Parsed) -> usize {
|
|
let mut flashed: Vec<_> = grid
|
|
.fields
|
|
.iter_mut()
|
|
.filter_map(|(p, energy)| {
|
|
*energy += 1;
|
|
(*energy == 10).then_some(*p)
|
|
})
|
|
.collect();
|
|
for p in flashed.clone() {
|
|
flash(grid, &p, &mut flashed);
|
|
}
|
|
for p in &flashed {
|
|
*grid.fields.get_mut(p).unwrap() = 0;
|
|
}
|
|
flashed.len()
|
|
}
|
|
|
|
fn flash(grid: &mut Parsed, position: &PositionND<2>, flashed: &mut Vec<PositionND<2>>) {
|
|
for n in position.neighbors() {
|
|
if let Some(p) = grid.fields.get_mut(&n) {
|
|
*p += 1;
|
|
if p == &10 {
|
|
flashed.push(n);
|
|
flash(grid, &n, flashed);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
fn main() {
|
|
let input = parse_input(&read_file(DAY));
|
|
println!("Part 1: {}", part1(&input));
|
|
println!("Part 2: {}", part2(&input));
|
|
}
|
|
|
|
#[cfg(test)]
|
|
mod tests {
|
|
use super::*;
|
|
use aoc2021::*;
|
|
|
|
const TEST_INPUT: &str = "5483143223
|
|
2745854711
|
|
5264556173
|
|
6141336146
|
|
6357385478
|
|
4167524645
|
|
2176841721
|
|
6882881134
|
|
4846848554
|
|
5283751526";
|
|
|
|
test!(part1() == 1656);
|
|
test!(part2() == 195);
|
|
bench!(part1() == 1741);
|
|
bench!(part2() == 440);
|
|
bench_input!(Grid::len => 100);
|
|
}
|