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|
#![allow(dead_code)]
#![allow(unused_variables)]
use advent_of_code::prelude::*;
#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash, Default)]
pub enum Tile {
#[default]
Floor,
Start,
UpDown,
LeftRight,
UpRight,
UpLeft,
DownRight,
DownLeft,
}
impl Tile {
fn points_left(&self) -> bool {
matches!(
self,
Self::Start | Self::LeftRight | Self::UpLeft | Self::DownLeft
)
}
fn points_right(&self) -> bool {
matches!(
self,
Self::Start | Self::LeftRight | Self::UpRight | Self::DownRight
)
}
fn points_up(&self) -> bool {
matches!(
self,
Self::Start | Self::UpDown | Self::UpLeft | Self::UpRight
)
}
fn points_down(&self) -> bool {
matches!(
self,
Self::Start | Self::UpDown | Self::DownLeft | Self::DownRight
)
}
fn connects(
&self,
other: &Self,
direction: (Ordering, Ordering),
) -> bool {
match direction {
(Ordering::Less, Ordering::Equal) => {
self.points_up() && other.points_down()
}
(Ordering::Greater, Ordering::Equal) => {
self.points_down() && other.points_up()
}
(Ordering::Equal, Ordering::Less) => {
self.points_left() && other.points_right()
}
(Ordering::Equal, Ordering::Greater) => {
self.points_right() && other.points_left()
}
_ => false,
}
}
}
pub fn parse(fh: File) -> Result<Grid<Tile>> {
Ok(parse::grid(parse::raw_lines(fh), |c, _, _| match c {
b'.' => Tile::Floor,
b'S' => Tile::Start,
b'|' => Tile::UpDown,
b'-' => Tile::LeftRight,
b'L' => Tile::UpRight,
b'J' => Tile::UpLeft,
b'F' => Tile::DownRight,
b'7' => Tile::DownLeft,
_ => panic!("bad tile {c}"),
}))
}
pub fn part1(map: Grid<Tile>) -> Result<i64> {
let mut cur = map
.indexed_cells()
.find_map(|(pos, tile)| {
if *tile == Tile::Start {
Some(pos)
} else {
None
}
})
.unwrap();
let mut pipe_loop = vec![];
while pipe_loop.len() < 2
|| pipe_loop[0] != pipe_loop[pipe_loop.len() - 1]
{
pipe_loop.push(cur);
for pos in map.adjacent(cur.0, cur.1, false) {
if pipe_loop.len() > 1 && pos == pipe_loop[pipe_loop.len() - 2] {
continue;
}
if map[cur.0][cur.1].connects(
&map[pos.0][pos.1],
(pos.0.cmp(&cur.0), pos.1.cmp(&cur.1)),
) {
cur = pos;
break;
}
}
}
Ok(i64::try_from(pipe_loop.len() - 1).unwrap() / 2)
}
pub fn part2(_: Grid<Tile>) -> Result<i64> {
todo!()
}
#[test]
fn test() {
assert_eq!(
part1(parse(parse::data(2023, 10).unwrap()).unwrap()).unwrap(),
7086
);
assert_eq!(
part2(parse(parse::data(2023, 10).unwrap()).unwrap()).unwrap(),
0
);
}
|
