day(11): add solution

Signed-off-by: Matej Focko <mfocko@redhat.com>

samples/day11.txt

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

src/bin/day11.rs

@@ -0,0 +1,113 @@
+use std::collections::HashSet;
+
+use itertools::iproduct;
+
+use aoc_2023::*;
+
+type Output1 = u64;
+type Output2 = Output1;
+
+struct Day11 {
+    galaxies: Vec<(i64, i64)>,
+    empty_ys: HashSet<usize>,
+    empty_xs: HashSet<usize>,
+}
+impl Solution<Output1, Output2> for Day11 {
+    fn new<P: AsRef<Path>>(pathname: P) -> Self {
+        let lines: Vec<String> = file_to_lines(pathname);
+        let map = lines.iter().map(|l| l.chars().collect_vec()).collect_vec();
+
+        let galaxies = iproduct!((0..map.len()), (0..map[0].len()))
+            .filter_map(|(y, x)| {
+                (map[y][x] != '.').then(|| (y.try_into().unwrap(), x.try_into().unwrap()))
+            })
+            .collect();
+
+        let empty_ys = map
+            .iter()
+            .enumerate()
+            .filter(|&(_, l)| l.iter().all(|&c| c == '.'))
+            .map(|(y, _)| y)
+            .collect();
+
+        let empty_xs = (0..map[0].len())
+            .filter(|&x| (0..map[x].len()).all(|y| map[y][x] == '.'))
+            .collect();
+
+        Self {
+            galaxies,
+            empty_ys,
+            empty_xs,
+        }
+    }
+
+    fn part_1(&mut self) -> Output1 {
+        (0..self.galaxies.len() - 1)
+            .map(|i| {
+                let (y0, x0) = self.galaxies[i];
+
+                (i + 1..self.galaxies.len())
+                    .map(|j| {
+                        let (y1, x1) = self.galaxies[j];
+
+                        let mut xd = x0.abs_diff(x1);
+                        let mut yd = y0.abs_diff(y1);
+
+                        let (min_x, max_x) = if x0 <= x1 { (x0, x1) } else { (x1, x0) };
+                        for x in &self.empty_xs {
+                            if (min_x as usize) < *x && *x < max_x as usize {
+                                xd += 1;
+                            }
+                        }
+
+                        for y in &self.empty_ys {
+                            if (y0 as usize) < *y && *y < (y1 as usize) {
+                                yd += 1;
+                            }
+                        }
+
+                        xd + yd
+                    })
+                    .sum::<u64>()
+            })
+            .sum::<u64>()
+    }
+
+    fn part_2(&mut self) -> Output2 {
+        (0..self.galaxies.len() - 1)
+            .map(|i| {
+                let (y0, x0) = self.galaxies[i];
+
+                (i + 1..self.galaxies.len())
+                    .map(|j| {
+                        let (y1, x1) = self.galaxies[j];
+
+                        let mut xd = x0.abs_diff(x1);
+                        let mut yd = y0.abs_diff(y1);
+
+                        let (min_x, max_x) = if x0 <= x1 { (x0, x1) } else { (x1, x0) };
+                        for x in &self.empty_xs {
+                            if (min_x as usize) < *x && *x < max_x as usize {
+                                xd += 999999;
+                            }
+                        }
+
+                        for y in &self.empty_ys {
+                            if (y0 as usize) < *y && *y < (y1 as usize) {
+                                yd += 999999;
+                            }
+                        }
+
+                        xd + yd
+                    })
+                    .sum::<u64>()
+            })
+            .sum::<u64>()
+    }
+}
+
+fn main() -> Result<()> {
+    Day11::main()
+}
+
+test_sample!(day_11, Day11, 374, 82000210);