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static DAY: u8 = 11;
fn main() {
let input = advent::read_lines(DAY);
println!("{DAY}a: {}", sum_path_lengths(&input));
println!("{DAY}b: {}", 0);
}
#[derive(PartialEq, Eq)]
struct Position {
x: isize,
y: isize,
}
struct GalaxyMap {
galaxies: Vec<Position>,
width: isize,
height: isize,
}
impl GalaxyMap {
fn new(input: &[String]) -> GalaxyMap {
let mut galaxies = Vec::new();
for (y, line) in input.iter().enumerate() {
for (x, c) in line.chars().enumerate() {
let pos = Position { x: x as isize, y: y as isize };
if c == '#' {
galaxies.push(pos);
}
}
}
let width = input[0].len() as isize;
let height = input.len() as isize;
GalaxyMap { galaxies, width, height }
}
fn expand_space(&mut self) {
let mut columns = Vec::new();
for x in 0 .. self.width {
if !self.galaxies.iter().any(|pos| pos.x == x) {
columns.push(x);
}
}
let mut rows = Vec::new();
for y in 0 .. self.height {
if !self.galaxies.iter().any(|pos| pos.y == y) {
rows.push(y);
}
}
for x in columns.iter().rev() {
for galaxy in self.galaxies.iter_mut().filter(|pos| pos.x > *x) {
galaxy.x += 1;
}
self.width += 1;
}
for y in rows.iter().rev() {
for galaxy in self.galaxies.iter_mut().filter(|pos| pos.y > *y) {
galaxy.y += 1;
}
self.height += 1;
}
}
fn _print_map(&self) {
for y in 0 .. self.height {
for x in 0 .. self.width {
if self.galaxies.iter().any(|pos| *pos == Position { x, y }) {
print!("#");
} else {
print!(".");
}
}
println!();
}
}
fn calculate_distances(&self) -> Vec<isize> {
let mut distances = Vec::new();
for (i, pos1) in self.galaxies.iter().enumerate() {
for pos2 in self.galaxies.iter().skip(i+1) {
let distance = pos1.x.abs_diff(pos2.x) + pos1.y.abs_diff(pos2.y);
distances.push(distance as isize);
}
}
distances
}
}
fn sum_path_lengths(input: &[String]) -> isize {
let mut galaxymap = GalaxyMap::new(input);
galaxymap.expand_space();
galaxymap.calculate_distances()
.iter()
.sum()
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn test() {
let input = [
"...#......",
".......#..",
"#.........",
"..........",
"......#...",
".#........",
".........#",
"..........",
".......#..",
"#...#.....",
].iter().map(|&x| String::from(x)).collect::<Vec<_>>();
assert_eq!(sum_path_lengths(&input), 374);
}
}
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