diff --git a/11/day11.rs b/11/day11.rs new file mode 100644 index 0000000..6fcdaa1 --- /dev/null +++ b/11/day11.rs @@ -0,0 +1,74 @@ +use std::io::{self, BufRead}; + +const ADD_TO_EMPTY1: usize = 1; +const ADD_TO_EMPTY2: usize = 1_000_000-1; +fn add_empty_columns(galaxy_positions: &mut Vec<(usize, usize)>, add_to_empty: usize) { + let mut last_x: usize = galaxy_positions[0].0; + let mut empty_columns: usize = 0; + for i in 1..galaxy_positions.len() { + if galaxy_positions[i].0 > last_x + 1 { + empty_columns += (galaxy_positions[i].0 - last_x - 1) * add_to_empty; + } + last_x = galaxy_positions[i].0; + galaxy_positions[i].0 += empty_columns; + } +} + +fn get_distance_sum(galaxy_positions: &Vec<(usize, usize)>) -> usize { + let mut distance_sum: usize = 0; + for i in 0..galaxy_positions.len() - 1 { + for j in i+1..galaxy_positions.len() { + // println!("{}<->{}: {}", i, j, galaxy_positions[i].0.abs_diff(galaxy_positions[j].0) + galaxy_positions[i].1.abs_diff(galaxy_positions[j].1)); + distance_sum += galaxy_positions[i].0.abs_diff(galaxy_positions[j].0); + distance_sum += galaxy_positions[i].1.abs_diff(galaxy_positions[j].1); + } + } + return distance_sum; +} + +fn main() { + // let input = "example.txt"; + let input = "input.txt"; + let lines = read_lines(&input); + let mut galaxy_positions1: Vec<(usize, usize)> = Vec::new(); + let mut galaxy_positions2: Vec<(usize, usize)> = Vec::new(); + galaxy_positions1.reserve(300); + galaxy_positions2.reserve(300); + let mut y1: usize = 0; + let mut y2: usize = 0; + for line in lines.map(|r| r.ok().unwrap()) { + let mut galaxies = line.chars().enumerate().filter(|(_, c)| *c == '#'); + if let Some((x, _)) = galaxies.next() { + galaxy_positions1.push((x, y1)); + galaxy_positions2.push((x, y2)); + while let Some((x, _)) = galaxies.next() { + galaxy_positions1.push((x, y1)); + galaxy_positions2.push((x, y2)); + } + } + else { // empty lines are double the size + y1 += ADD_TO_EMPTY1; + y2 += ADD_TO_EMPTY2; + } + y1 += 1; + y2 += 1; + } + // sort by x + galaxy_positions1.sort_unstable_by(|a ,b| a.0.cmp(&b.0)); + galaxy_positions2.sort_unstable_by(|a ,b| a.0.cmp(&b.0)); + add_empty_columns(&mut galaxy_positions1, ADD_TO_EMPTY1); + add_empty_columns(&mut galaxy_positions2, ADD_TO_EMPTY2); + let distance_sum1: usize = get_distance_sum(&galaxy_positions1); + println!("Sum of galaxy distances: (1): {}", distance_sum1); + let distance_sum2: usize = get_distance_sum(&galaxy_positions2); + println!("Sum of galaxy distances: (2): {}", distance_sum2); +} + + +fn read_lines
(filename: P) -> io::Lines