advent-of-code/2022
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day(08): address DRY

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Signed-off-by: Matej Focko <mfocko@redhat.com>
This commit is contained in:
Matej Focko 2022-12-08 12:50:14 +01:00
parent e419087f1c
commit 7b364e35a3
Signed by: mfocko
GPG key ID: 7C47D46246790496
1 changed files with 51 additions and 52 deletions
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103
src/bin/day08.rs
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@ -10,44 +10,41 @@ use tracing_subscriber::EnvFilter;
type Input = Vec<Vec<i8>>;
type Output = usize;
type Position = Vector2D<usize>;
type Visited = BTreeSet<Position>;
fn count_in(trees: &Input, counted: &mut BTreeSet<(usize, usize)>, swap: bool) {
fn folder(
trees: &Input,
counted: &mut BTreeSet<(usize, usize)>,
mut x: usize,
mut y: usize,
swap: bool,
tallest: i8,
) -> i8 {
if swap {
(x, y) = (y, x);
}
if trees[y][x] > tallest {
counted.insert((x, y));
}
max(tallest, trees[y][x])
}
(0..trees.len()).for_each(|y| {
(0..trees[y].len()).fold(-1, |tallest, x| folder(trees, counted, x, y, swap, tallest));
(0..trees[y].len()).rfold(-1, |tallest, x| folder(trees, counted, x, y, swap, tallest));
})
}
fn count_in_rows(trees: &Input, counted: &mut BTreeSet<(usize, usize)>) {
trees.iter().enumerate().for_each(|(y, row)| {
row.iter().enumerate().fold(-1, |tallest, (x, tree)| {
if *tree > tallest {
counted.insert((x, y));
}
max(*tree, tallest)
});
row.iter().enumerate().rfold(-1, |tallest, (x, tree)| {
if *tree > tallest {
counted.insert((x, y));
}
max(*tree, tallest)
});
});
count_in(trees, counted, false)
}
fn count_in_columns(trees: &Input, counted: &mut BTreeSet<(usize, usize)>) {
(0..trees[0].len()).for_each(|x| {
(0..trees.len()).fold(-1, |tallest, y| {
if trees[y][x] > tallest {
counted.insert((x, y));
}
max(tallest, trees[y][x])
});
(0..trees.len()).rev().fold(-1, |tallest, y| {
if trees[y][x] > tallest {
counted.insert((x, y));
}
max(tallest, trees[y][x])
});
});
count_in(trees, counted, true)
}
fn part_1(input: &Input) -> Output {
@ -63,27 +60,29 @@ fn in_range(trees: &Input, x: i32, y: i32) -> bool {
y >= 0 && y < trees.len() as i32 && x >= 0 && x < trees[y as usize].len() as i32
}
fn count_visible(trees: &Input, x: i32, y: i32, dx: i32, dy: i32) -> usize {
let max_height = trees[y as usize][x as usize];
let mut d = 1;
let mut visible = 0;
while in_range(trees, x + d * dx, y + d * dy) {
visible += 1;
if trees[(y + d * dy) as usize][(x + d * dx) as usize] >= max_height {
break;
}
d += 1;
}
visible as usize
}
fn compute_scenic_score(trees: &Input, x: i32, y: i32) -> usize {
vec![(0, 1), (1, 0), (0, -1), (-1, 0)]
.iter()
.map(|&(dx, dy)| {
let max_height = trees[y as usize][x as usize];
let mut d = 1;
let mut visible = 0;
while in_range(trees, x + d * dx, y + d * dy) {
visible += 1;
if trees[(y + d * dy) as usize][(x + d * dx) as usize] >= max_height {
break;
}
d += 1;
}
visible as usize
})
.map(|&(dx, dy)| count_visible(trees, x, y, dx, dy))
.product()
}