Solve day 11

README.md

@@ -11,18 +11,19 @@ Solutions for [Advent of Code](https://adventofcode.com/) in [Rust](https://www.
 
 | Day | Part 1 | Part 2 |
 | :---: | :---: | :---:  |
-| [Day 1](./src/bin/01.rs) | `70.7µs` | `851.5µs` |
-| [Day 2](./src/bin/02.rs) | `38.6µs` | `48.7µs` |
-| [Day 3](./src/bin/03.rs) | `232.8µs` | `246.2µs` |
-| [Day 4](./src/bin/04.rs) | `202.3µs` | `195.7µs` |
-| [Day 5](./src/bin/05.rs) | `21.1µs` | `74.4µs` |
-| [Day 6](./src/bin/06.rs) | `654.0ns` | `504.0ns` |
-| [Day 7](./src/bin/07.rs) | `295.7µs` | `287.5µs` |
-| [Day 8](./src/bin/08.rs) | `150.2µs` | `496.9µs` |
-| [Day 9](./src/bin/09.rs) | `171.6µs` | `167.1µs` |
-| [Day 10](./src/bin/10.rs) | `250.2µs` | `258.5µs` |
-
-**Total: 4.06ms**
+| [Day 1](./src/bin/01.rs) | `70.8µs` | `842.1µs` |
+| [Day 2](./src/bin/02.rs) | `38.9µs` | `48.4µs` |
+| [Day 3](./src/bin/03.rs) | `229.2µs` | `245.5µs` |
+| [Day 4](./src/bin/04.rs) | `198.9µs` | `194.8µs` |
+| [Day 5](./src/bin/05.rs) | `21.0µs` | `74.1µs` |
+| [Day 6](./src/bin/06.rs) | `396.0ns` | `335.0ns` |
+| [Day 7](./src/bin/07.rs) | `290.3µs` | `301.8µs` |
+| [Day 8](./src/bin/08.rs) | `158.9µs` | `500.5µs` |
+| [Day 9](./src/bin/09.rs) | `172.2µs` | `166.7µs` |
+| [Day 10](./src/bin/10.rs) | `254.4µs` | `257.7µs` |
+| [Day 11](./src/bin/11.rs) | `504.5µs` | `492.8µs` |
+
+**Total: 5.06ms**
 <!--- benchmarking table --->
 
 ---

data/examples/11.txt

@@ -0,0 +1,10 @@
+...#......
+.......#..
+#.........
+..........
+......#...
+.#........
+.........#
+..........
+.......#..
+#...#.....

src/bin/11.rs

@@ -0,0 +1,71 @@
+use itertools::Itertools;
+use rustc_hash::FxHashSet;
+use std::cmp::{max, min};
+advent_of_code::solution!(11);
+
+fn solve(input: &str, expansion: isize) -> isize {
+    let galaxies: Vec<(isize, isize)> = input
+        .lines()
+        .enumerate()
+        .flat_map(|(y, line)| {
+            line.chars()
+                .enumerate()
+                .filter(|(_, char)| *char == '#')
+                .map(move |(x, _)| (x as isize, y as isize))
+        })
+        .collect();
+
+    let columns_with_galaxies: FxHashSet<isize> = galaxies.iter().map(|(x, _)| *x).collect();
+
+    let rows_with_galaxies: FxHashSet<isize> = galaxies.iter().map(|(_, y)| *y).collect();
+
+    let columns_without_galaxies: Vec<isize> = (0..*columns_with_galaxies.iter().max().unwrap())
+        .filter(|x| !columns_with_galaxies.contains(x))
+        .collect();
+
+    let rows_without_galaxies: Vec<isize> = (0..*rows_with_galaxies.iter().max().unwrap())
+        .filter(|y| !rows_with_galaxies.contains(y))
+        .collect();
+
+    galaxies
+        .iter()
+        .map(|(x, y)| {
+            let dx = columns_without_galaxies.iter().filter(|c| *c < x).count() as isize;
+
+            let dy = rows_without_galaxies.iter().filter(|c| *c < y).count() as isize;
+
+            ((x, dx), (y, dy))
+        })
+        .tuple_combinations()
+        .map(|(((x1, dx1), (y1, dy1)), ((x2, dx2), (y2, dy2)))| {
+            (x1 - x2).abs()
+                + (y1 - y2).abs()
+                + ((dx1 - dx2).abs() + (dy1 - dy2).abs()) * (expansion - 1)
+        })
+        .sum()
+}
+
+pub fn part_one(input: &str) -> Option<isize> {
+    Some(solve(input, 2))
+}
+
+pub fn part_two(input: &str) -> Option<isize> {
+    Some(solve(input, 1_000_000))
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_solve() {
+        let result = solve(&advent_of_code::template::read_file("examples", DAY), 2);
+        assert_eq!(result, 374);
+
+        let result = solve(&advent_of_code::template::read_file("examples", DAY), 10);
+        assert_eq!(result, 1030);
+
+        let result = solve(&advent_of_code::template::read_file("examples", DAY), 100);
+        assert_eq!(result, 8410);
+    }
+}