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use crate::prelude::*;
#[derive(Debug, Copy, Clone, Hash, PartialEq, Eq)]
struct Point3D {
x: i64,
y: i64,
z: i64,
}
impl Point3D {
fn new(x: i64, y: i64, z: i64) -> Self {
Self { x, y, z }
}
}
#[derive(Debug, Clone, Hash, PartialEq, Eq)]
struct Range3D {
x: std::ops::RangeInclusive<i64>,
y: std::ops::RangeInclusive<i64>,
z: std::ops::RangeInclusive<i64>,
}
impl Range3D {
fn new(
x: std::ops::RangeInclusive<i64>,
y: std::ops::RangeInclusive<i64>,
z: std::ops::RangeInclusive<i64>,
) -> Self {
Self { x, y, z }
}
fn contains(&self, point: &Point3D) -> bool {
self.x.contains(&point.x)
&& self.y.contains(&point.y)
&& self.z.contains(&point.z)
}
}
#[derive(Debug, Clone)]
struct Rule {
on: bool,
range: Range3D,
}
impl Rule {
fn parse(line: &str) -> Self {
let captures = regex_captures!(
r"^(\w+) x=(-?\d+)..(-?\d+),y=(-?\d+)..(-?\d+),z=(-?\d+)..(-?\d+)$",
line
)
.unwrap();
Self {
on: &captures[1] == "on",
range: Range3D::new(
captures[2].parse().unwrap()..=captures[3].parse().unwrap(),
captures[4].parse().unwrap()..=captures[5].parse().unwrap(),
captures[6].parse().unwrap()..=captures[7].parse().unwrap(),
),
}
}
fn contains(&self, point: &Point3D) -> Option<bool> {
if self.range.contains(point) {
Some(self.on)
} else {
None
}
}
}
#[derive(Debug)]
pub struct Reactor {
rules: Vec<Rule>,
}
impl Reactor {
fn parse(lines: impl Iterator<Item = String>) -> Self {
Self {
rules: lines.map(|line| Rule::parse(&line)).collect(),
}
}
fn on(&self, point: &Point3D) -> bool {
for rule in self.rules.iter().rev() {
if let Some(on) = rule.contains(point) {
return on;
}
}
false
}
}
pub fn parse(fh: File) -> Result<Reactor> {
Ok(Reactor::parse(parse::lines(fh)))
}
pub fn part1(reactor: Reactor) -> Result<i64> {
let mut total = 0;
for x in -50..=50 {
for y in -50..=50 {
for z in -50..=50 {
if reactor.on(&Point3D::new(x, y, z)) {
total += 1;
}
}
}
}
Ok(total)
}
pub fn part2(reactor: Reactor) -> Result<i64> {
let mut x = vec![];
let mut y = vec![];
let mut z = vec![];
for rule in &reactor.rules {
x.push(*rule.range.x.start());
x.push(rule.range.x.end() + 1);
y.push(*rule.range.y.start());
y.push(rule.range.y.end() + 1);
z.push(*rule.range.z.start());
z.push(rule.range.z.end() + 1);
}
x.sort_unstable();
y.sort_unstable();
z.sort_unstable();
let mut total = 0;
for i in 0..(x.len() - 1) {
eprintln!("{}", i);
for j in 0..(y.len() - 1) {
for k in 0..(z.len() - 1) {
if reactor.on(&Point3D::new(x[i], y[j], z[k])) {
total += (x[i + 1] - x[i])
* (y[j + 1] - y[j])
* (z[k + 1] - z[k])
}
}
}
}
Ok(total)
}
#[test]
fn test() {
assert_eq!(
part1(parse(parse::data(2021, 22).unwrap()).unwrap()).unwrap(),
570915
);
assert_eq!(
part2(parse(parse::data(2021, 22).unwrap()).unwrap()).unwrap(),
1268313839428137
);
}
|
