jdkaplan/advent-of-code
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Cleanup

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This commit is contained in:
Jeremy Kaplan 2022-12-07 23:26:35 -08:00
commit de08913fba
1 changed files with 31 additions and 57 deletions
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78
2022/src/bin/day08.rs
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@ -5,7 +5,7 @@ const INPUT: &str = include_str!("../../input/day08.txt");
fn main() { fn main() {
let grid = Grid::new(INPUT); let grid = Grid::new(INPUT);
let visibility = grid.count_visible(); let visibility = grid.find_visible();
let part1 = visibility.iter().filter(|(_, v)| !v.is_empty()).count(); let part1 = visibility.iter().filter(|(_, v)| !v.is_empty()).count();
println!("Part 1: {}", part1); println!("Part 1: {}", part1);
@ -54,70 +54,42 @@ impl Grid {
Self { map, rows, cols } Self { map, rows, cols }
} }
fn count_visible(&self) -> HashMap<RC, HashSet<Visibility>> { fn find_visible(&self) -> HashMap<RC, HashSet<Visibility>> {
// Assume all trees are visible from all sides until we learn that they're blocked. // Assume all trees are visible from all sides until we learn that they're blocked.
let mut visibility: HashMap<RC, HashSet<Visibility>> = HashMap::new(); let mut visibility: HashMap<RC, HashSet<Visibility>> = HashMap::new();
for r in 0..self.rows { for (r, c) in itertools::iproduct!(0..self.rows, 0..self.cols) {
for c in 0..self.cols {
visibility.insert((r, c), Visibility::all()); visibility.insert((r, c), Visibility::all());
} }
}
// Now see what each tree would block.
for (r1, c1) in itertools::iproduct!(0..self.rows, 0..self.cols) { for (r1, c1) in itertools::iproduct!(0..self.rows, 0..self.cols) {
let big = (r1, c1); let height = self.map[&(r1, c1)];
let h1 = self.map[&big];
for (r2, c2) in (0..r1).map(|r| (r, c1)) { use Visibility::*;
let lil = (r2, c2); let block: Vec<(Visibility, Vec<RC>)> = vec![
let h2 = self.map[&lil]; (Top, (0..r1).map(|r| (r, c1)).collect()),
(Bottom, ((r1 + 1)..self.rows).map(|r| (r, c1)).collect()),
(Right, (0..c1).map(|c| (r1, c)).collect()),
(Left, ((c1 + 1)..self.cols).map(|c| (r1, c)).collect()),
];
if h1 >= h2 { for (vis, ray) in block {
visibility.entry(lil).and_modify(|v| { for rc in ray {
v.remove(&Visibility::Bottom); if height >= self.map[&rc] {
visibility.entry(rc).and_modify(|v| {
v.remove(&vis);
}); });
} }
} }
for (r2, c2) in ((r1 + 1)..self.rows).map(|r| (r, c1)) {
let lil = (r2, c2);
let h2 = self.map[&lil];
if h1 >= h2 {
visibility.entry(lil).and_modify(|v| {
v.remove(&Visibility::Top);
});
}
}
for (r2, c2) in (0..c1).map(|c| (r1, c)) {
let lil = (r2, c2);
let h2 = self.map[&lil];
if h1 >= h2 {
visibility.entry(lil).and_modify(|v| {
v.remove(&Visibility::Right);
});
}
}
for (r2, c2) in ((c1 + 1)..self.cols).map(|c| (r1, c)) {
let lil = (r2, c2);
let h2 = self.map[&lil];
if h1 >= h2 {
visibility.entry(lil).and_modify(|v| {
v.remove(&Visibility::Left);
});
}
} }
} }
visibility visibility
} }
fn score_views(&self) -> HashMap<RC, u64> { fn score_views(&self) -> HashMap<RC, usize> {
let mut scene: HashMap<RC, u64> = HashMap::new(); let mut scene: HashMap<RC, usize> = HashMap::new();
for (r1, c1) in itertools::iproduct!(0..self.rows, 0..self.cols) { for (r1, c1) in itertools::iproduct!(0..self.rows, 0..self.cols) {
let big = (r1, c1); let big = (r1, c1);
@ -125,19 +97,21 @@ impl Grid {
let mut score = 1; let mut score = 1;
let blockage = |rc: &RC| -> bool { self.map[rc] >= h1 };
let up = (0..r1).rev().map(|r| (r, c1)); let up = (0..r1).rev().map(|r| (r, c1));
score *= take_until(up, |rc| self.map[rc] >= h1).len(); score *= take_until(up, blockage).len();
let down = ((r1 + 1)..self.rows).map(|r| (r, c1)); let down = ((r1 + 1)..self.rows).map(|r| (r, c1));
score *= take_until(down, |rc| self.map[rc] >= h1).len(); score *= take_until(down, blockage).len();
let left = (0..c1).rev().map(|c| (r1, c)); let left = (0..c1).rev().map(|c| (r1, c));
score *= take_until(left, |rc| self.map[rc] >= h1).len(); score *= take_until(left, blockage).len();
let right = ((c1 + 1)..self.cols).map(|c| (r1, c)); let right = ((c1 + 1)..self.cols).map(|c| (r1, c));
score *= take_until(right, |rc| self.map[rc] >= h1).len(); score *= take_until(right, blockage).len();
scene.insert(big, score as u64); scene.insert(big, score);
} }
scene scene