From 09e0d81ffeb3ccf44fbaa86dd79f81adf2db1ca3 Mon Sep 17 00:00:00 2001
From: Matej Focko <mfocko@redhat.com>
Date: Mon, 11 Dec 2023 10:41:44 +0100
Subject: [PATCH] day(11): factor out the solution for any factor

Signed-off-by: Matej Focko <mfocko@redhat.com>
---
 src/bin/day11.rs | 116 +++++++++++++++++++++++------------------------
 1 file changed, 58 insertions(+), 58 deletions(-)

diff --git a/src/bin/day11.rs b/src/bin/day11.rs
index db30db3..efb48f4 100644
--- a/src/bin/day11.rs
+++ b/src/bin/day11.rs
@@ -12,6 +12,43 @@ struct Day11 {
     empty_ys: HashSet<usize>,
     empty_xs: HashSet<usize>,
 }
+
+impl Day11 {
+    fn solve(&self, factor: u64) -> u64 {
+        let to_add = factor - 1;
+
+        (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 += to_add;
+                            }
+                        }
+
+                        for y in &self.empty_ys {
+                            if (y0 as usize) < *y && *y < (y1 as usize) {
+                                yd += to_add;
+                            }
+                        }
+
+                        xd + yd
+                    })
+                    .sum::<u64>()
+            })
+            .sum::<u64>()
+    }
+}
+
 impl Solution<Output1, Output2> for Day11 {
     fn new<P: AsRef<Path>>(pathname: P) -> Self {
         let lines: Vec<String> = file_to_lines(pathname);
@@ -42,67 +79,11 @@ impl Solution<Output1, Output2> for Day11 {
     }
 
     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>()
+        self.solve(2)
     }
 
     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>()
+        self.solve(1000000)
     }
 }
 
@@ -111,3 +92,22 @@ fn main() -> Result<()> {
 }
 
 test_sample!(day_11, Day11, 374, 82000210);
+
+#[cfg(test)]
+mod day_11_extended {
+    use super::*;
+
+    #[test]
+    fn solve_for_10() {
+        let path = Day11::get_sample(2);
+        let day = Day11::new(path);
+        assert_eq!(day.solve(10), 1030);
+    }
+
+    #[test]
+    fn solve_for_100() {
+        let path = Day11::get_sample(2);
+        let day = Day11::new(path);
+        assert_eq!(day.solve(100), 8410);
+    }
+}