kageru/advent-of-code
1
0
Fork 0
Code Issues 1 Pull Requests Releases Wiki Activity

optimize day 11

This commit is contained in:
kageru 2023-12-11 10:14:25 +01:00
parent bff0e7601b
commit 61edcdb649
1 changed files with 16 additions and 16 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

32
2023/src/bin/day11.rs
View File

@ -13,32 +13,32 @@ fn parse_input(raw: &str) -> Parsed {
.enumerate() .enumerate()
.flat_map(|(x, l)| l.bytes().enumerate().filter_map(move |(y, b)| (b == b'#').then_some((x, y)))) .flat_map(|(x, l)| l.bytes().enumerate().filter_map(move |(y, b)| (b == b'#').then_some((x, y))))
.collect_vec(); .collect_vec();
let &xmax = galaxies.iter().map(|(x, _)| x).max().unwrap(); let max = raw.lines().next().unwrap().len();
let &ymax = galaxies.iter().map(|(_, y)| y).max().unwrap(); let mut xs = vec![true; max];
let mut xs = vec![true; xmax + 1]; let mut ys = vec![true; max];
let mut ys = vec![true; ymax + 1];
for &(x, y) in galaxies.iter() { for &(x, y) in galaxies.iter() {
xs[x] = false; xs[x] = false;
ys[y] = false; ys[y] = false;
} }
( (sliding_count(xs), sliding_count(ys), galaxies)
xs.into_iter().enumerate().filter_map(|(x, b)| b.then_some(x)).collect(),
ys.into_iter().enumerate().filter_map(|(y, b)| b.then_some(y)).collect(),
galaxies,
)
} }
fn distance<const FACTOR: usize>(x1: &I, x2: &I, empty: &[I]) -> I { fn sliding_count(bools: Vec<bool>) -> Vec<I> {
let smaller_x = x1.min(x2); bools
let bigger_x = x1.max(x2); .into_iter()
empty.iter().filter(|x| (smaller_x..=bigger_x).contains(x)).count() * FACTOR + bigger_x - smaller_x .scan(0, |prev, b| {
*prev += b as I;
Some(*prev)
})
.collect()
} }
fn solve<const FACTOR: usize>((empty_x, empty_y, galaxies): &Parsed) -> usize { fn solve<const FACTOR: usize>((x_offset, y_offset, galaxies): &Parsed) -> usize {
galaxies galaxies
.iter() .iter()
.map(|&(x, y)| (x + x_offset[x] * FACTOR, y + y_offset[y] * FACTOR))
.tuple_combinations() .tuple_combinations()
.map(|((x1, y1), (x2, y2))| distance::<FACTOR>(x1, x2, empty_x) + distance::<FACTOR>(y1, y2, empty_y)) .map(|((x1, y1), (x2, y2))| x1.abs_diff(x2) + y1.abs_diff(y2))
.sum() .sum()
} }
@ -67,5 +67,5 @@ boilerplate! {
}, },
bench1 == 9623138, bench1 == 9623138,
bench2 == 726820169514, bench2 == 726820169514,
bench_parse: |(a, b, c): &Parsed| (a.len(), b.len(), c.len()) => (9, 11, 432), bench_parse: |(a, b, c): &Parsed| (a.len(), b.len(), c.len()) => (140, 140, 432),
} }