aoc/2022/src/bin/day14.rs

332 lines
8.8 KiB
Rust

#![feature(test)]
use core::fmt;
use std::{str::FromStr, cmp::{min, max}};
use anyhow::Result;
use aoc::Solver;
#[cfg(feature = "gif")]
use gif::{Encoder, Repeat, Frame};
#[cfg(feature = "gif")]
use std::{borrow::Cow, fs::File};
// -- Runners --
fn main() -> Result<()> {
Day::solve()
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn part1_test1() -> Result<()> {
Day::test(Day::part1, "test-1", 24)
}
#[test]
fn part1_solution() -> Result<()> {
Day::test(Day::part1, "input", 1406)
}
#[test]
fn part2_test1() -> Result<()> {
Day::test(Day::part2, "test-1", 93)
}
#[test]
fn part2_solution() -> Result<()> {
Day::test(Day::part2, "input", 20870)
}
// Benchmarks
extern crate test;
#[bench]
#[ignore]
fn part1_bench(b: &mut test::Bencher) {
Day::benchmark(Day::part1, b)
}
#[bench]
#[ignore]
fn part2_bench(b: &mut test::Bencher) {
Day::benchmark(Day::part2, b)
}
}
#[derive(Debug)]
struct Point {
x: usize,
y: usize,
}
impl fmt::Display for Point {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
write!(f, "({}, {})", self.x, self.y)
}
}
impl FromStr for Point {
type Err = anyhow::Error;
fn from_str(s: &str) -> Result<Self, Self::Err> {
let (x, y) = s.split_once(",").unwrap();
let x = x.parse()?;
let y = y.parse()?;
Ok(Point{x, y})
}
}
#[derive(Debug)]
struct Path (Vec<Point>);
impl fmt::Display for Path {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
for (idx, point) in self.0.iter().enumerate() {
write!(f, "{}", point)?;
if idx+1 != self.0.len() {
write!(f, " -> ")?;
}
}
Ok(())
}
}
impl FromStr for Path {
type Err = anyhow::Error;
fn from_str(s: &str) -> Result<Self, Self::Err> {
let points = s
.split(" -> ")
.flat_map(Point::from_str)
.collect();
Ok(Path(points))
}
}
#[derive(Debug, Copy, Clone, PartialEq, Eq)]
enum Block {
Air,
Rock,
Sand,
Source,
Void,
}
struct Cave {
grid: Vec<Vec<Block>>,
source: usize,
size: (usize, usize),
}
impl<'a> Cave {
// Also returns the width and height of the cave
fn new(mut paths: Vec<Path>, floor: bool) -> Self {
// The sand source is at 500, 0
// This means that xmax starts at 500 and we know ymin is 0
let mut source = 500;
let (mut xmin, mut xmax, mut ymax) = (usize::MAX, source, 0);
for path in paths.iter() {
for point in path.0.iter() {
xmin = min(xmin, point.x);
xmax = max(xmax, point.x);
ymax = max(ymax, point.y);
}
}
if floor {
ymax += 2;
xmin = min(xmin, source - ymax);
xmax = max(xmax, source + ymax);
let path = Path(vec![Point{x: xmin, y: ymax}, Point{x: xmax, y: ymax}]);
paths.push(path);
}
for path in paths.iter_mut() {
for point in path.0.iter_mut() {
point.x -= xmin;
}
}
let width = xmax-xmin+1;
let height = ymax+1;
let mut grid = vec![vec![Block::Air; width]; height];
for path in paths {
for line in path.0.windows(2) {
let ystart = min(line[0].y, line[1].y);
let yend = max(line[0].y, line[1].y)+1;
for y in ystart..yend {
let xstart = min(line[0].x, line[1].x);
let xend = max(line[0].x, line[1].x)+1;
for x in xstart..xend {
grid[y][x] = Block::Rock;
}
}
}
}
source -= xmin;
grid[0][source] = Block::Source;
Self {
grid,
source,
size: (xmax-xmin+1, ymax+1)
}
}
fn from_str(s: &str, floor: bool) -> Self {
let paths = s
.lines()
.flat_map(Path::from_str)
.collect();
Self::new(paths, floor)
}
fn check(&self, x: isize, y: isize) -> Block {
if x < 0 || y < 0 || x >= self.size.0 as isize || y >= self.size.1 as isize {
return Block::Void;
}
return self.grid[y as usize][x as usize];
}
fn simulate_sand(&mut self) -> bool {
let (mut x, mut y): (isize, isize) = (self.source as isize, -1);
loop {
let positions = vec![
(x, y+1),
(x-1, y+1),
(x+1, y+1),
];
let mut moved = false;
for position in positions {
match self.check(position.0, position.1) {
// The sand can move into the position
Block::Air | Block::Source => {
// Update the coordinates
x = position.0;
y = position.1;
// Mark that the sand has moved
moved = true;
// Simulate the next step
break;
},
// This position is occupied, check the next position
Block::Rock | Block::Sand => continue,
// The sand fell into the void, any sand we add will also fall into the void
// Return false to signify this
Block::Void => return false,
}
}
// If the sand did not move, the sand has settled and we can return
if !moved {
let block = self.grid[y as usize][x as usize];
self.grid[y as usize][x as usize] = Block::Sand;
// If we replaced the source block we are also done
return block != Block::Source;
}
}
}
#[cfg(feature = "gif")]
fn frame(&self) -> Cow<[u8]> {
let buffer = self.grid.iter().flat_map(|line| line.iter().map(|block| match block {
Block::Air => 0,
Block::Rock => 1,
Block::Sand => 2,
Block::Source => 3,
Block::Void => 4,
}).collect::<Vec<_>>()).collect::<Vec<u8>>();
Cow::from(buffer)
}
fn count_sand(&self) -> usize {
self.grid.iter().flatten().filter(|&block| *block == Block::Sand).count()
}
}
#[cfg(feature = "gif")]
fn write_frame<T: std::io::Write>(encoder: &mut Encoder<T>, cave: &Cave, delay: u16) {
let mut frame = Frame::default();
frame.width = cave.size.0 as u16;
frame.height = cave.size.1 as u16;
frame.buffer = cave.frame();
frame.delay = delay;
encoder.write_frame(&frame).unwrap();
}
// -- Solution --
pub struct Day;
impl aoc::Solver for Day {
type Output1 = usize;
type Output2 = usize;
fn day() -> u8 {
14
}
fn part1(input: &str) -> Self::Output1 {
let mut cave = Cave::from_str(input, false);
#[cfg(feature = "gif")]
let color_map = &[0xFF, 0xFF, 0xFF, 0x00, 0x00, 0x00, 0xea, 0xc7, 0x99, 0xFF, 0x00, 0x00, 0x00, 0x00, 0xFF];
#[cfg(feature = "gif")]
let mut image = File::create("visualize/14/part1.gif").unwrap();
#[cfg(feature = "gif")]
let mut encoder = Encoder::new(&mut image, cave.size.0 as u16, cave.size.1 as u16, color_map).unwrap();
#[cfg(feature = "gif")]
encoder.set_repeat(Repeat::Infinite).unwrap();
#[cfg(feature = "gif")]
write_frame(&mut encoder, &mut cave, 100);
while cave.simulate_sand() {
#[cfg(feature = "gif")]
write_frame(&mut encoder, &mut cave, 1);
}
#[cfg(feature = "gif")]
write_frame(&mut encoder, &mut cave, 1000);
cave.count_sand()
}
fn part2(input: &str) -> Self::Output2 {
let mut cave = Cave::from_str(input, true);
#[cfg(feature = "gif")]
let color_map = &[0xFF, 0xFF, 0xFF, 0x00, 0x00, 0x00, 0xea, 0xc7, 0x99, 0xFF, 0x00, 0x00, 0x00, 0x00, 0xFF];
#[cfg(feature = "gif")]
let mut image = File::create("visualize/14/part2.gif").unwrap();
#[cfg(feature = "gif")]
let mut encoder = Encoder::new(&mut image, cave.size.0 as u16, cave.size.1 as u16, color_map).unwrap();
#[cfg(feature = "gif")]
encoder.set_repeat(Repeat::Infinite).unwrap();
#[cfg(feature = "gif")]
write_frame(&mut encoder, &mut cave, 100);
while cave.simulate_sand() {
#[cfg(feature = "gif")]
write_frame(&mut encoder, &mut cave, 1);
}
#[cfg(feature = "gif")]
write_frame(&mut encoder, &mut cave, 1000);
cave.count_sand()
}
}