Day 23 complete

1 files changed, 188 insertions, 21 deletions

diff --git a/2022/src/bin/day_23.rs b/2022/src/bin/day_23.rs
index 5f58dea..1267431 100644
--- a/2022/src/bin/day_23.rs
+++ b/2022/src/bin/day_23.rs
@@ -12,21 +12,31 @@ use std::{
 };
 
 fn main() -> Result<(), Box<dyn std::error::Error>> {
-    let input = fs::read_to_string("inputs/day_23_test.txt")?;
-    let mut elves = ElfMap::parser(&input).unwrap().1;
+    let input = fs::read_to_string("inputs/day_23.txt")?;
+    let elves = ElfMap::parser(&input).unwrap().1;
 
-    dbg!(&elves);
-    for _ in 0..10 {
-        elves.process_round();
-        dbg!(&elves);
+    {
+        let mut elves_1 = elves.clone();
+        for _ in 0..10 {
+            elves_1.process_round();
+        }
+        dbg!(elves_1.count_empty_ground());
     }
 
-    dbg!(elves.count_empty_ground());
+    {
+        let mut elves_2 = elves.clone();
+        for round in 1.. {
+            if !elves_2.process_round() {
+                dbg!(round);
+                break;
+            }
+        }
+    }
 
     Ok(())
 }
 
-#[derive(Debug, Clone)]
+#[derive(Debug, Clone, PartialEq, Eq)]
 struct ElfMap {
     elves: BTreeSet<Point>,
     check_order: VecDeque<Direction>,
@@ -81,7 +91,7 @@ impl ElfMap {
         )(input)
     }
 
-    fn process_round(&mut self) {
+    fn process_round(&mut self) -> bool {
         // key is destination!
         let mut elf_moves: BTreeMap<Point, Point> = BTreeMap::new();
         let mut conflict_moves: BTreeSet<Point> = BTreeSet::new();
@@ -98,6 +108,8 @@ impl ElfMap {
             }
         }
 
+        let any_elf_moved = elf_moves.len() > 0;
+
         // phase 2: move the elves
         for (dest, src) in elf_moves {
             self.elves.remove(&src);
@@ -109,6 +121,8 @@ impl ElfMap {
             .pop_front()
             .expect("Where did the directions go?");
         self.check_order.push_back(rotate);
+
+        any_elf_moved
     }
 
     fn find_elf_move(&self, elf: &Point) -> Option<Point> {
@@ -133,16 +147,13 @@ impl ElfMap {
     }
 
     fn count_empty_ground(&self) -> i64 {
-        let mut min_x = 0;
-        let mut min_y = 0;
-        let mut max_x = 0;
-        let mut max_y = 0;
-        for elf in &self.elves {
-            min_x = min_x.min(elf.x);
-            min_y = min_y.min(elf.y);
-            max_x = max_x.max(elf.x);
-            max_y = max_y.max(elf.y);
-        }
+        let elf_x = self.elves.iter().map(|elf| elf.x);
+        let min_x = elf_x.clone().min().unwrap_or(0);
+        let max_x = elf_x.max().unwrap_or(0);
+
+        let elf_y = self.elves.iter().map(|elf| elf.y);
+        let min_y = elf_y.clone().min().unwrap_or(0);
+        let max_y = elf_y.max().unwrap_or(0);
 
         let all_ground = (max_x - min_x + 1) * (max_y - min_y + 1);
         let covered_ground = self.elves.len() as i64;
@@ -156,8 +167,8 @@ impl Point {
             None => ((-1..=1), (-1..=1)),
             Some(Direction::North) => ((-1..=-1), (-1..=1)),
             Some(Direction::South) => ((1..=1), (-1..=1)),
-            Some(Direction::East) => ((-1..=1), (-1..=-1)),
-            Some(Direction::West) => ((-1..=1), (1..=1)),
+            Some(Direction::West) => ((-1..=1), (-1..=-1)),
+            Some(Direction::East) => ((-1..=1), (1..=1)),
         };
 
         y_range
@@ -171,3 +182,159 @@ impl Point {
             .collect()
     }
 }
+
+#[test]
+fn follows_the_example() {
+    let mut elf_map = ElfMap::parser(
+        r"..............
+..............
+.......#......
+.....###.#....
+...#...#.#....
+....#...##....
+...#.###......
+...##.#.##....
+....#..#......
+..............
+..............
+..............",
+    )
+    .unwrap()
+    .1;
+
+    elf_map.process_round();
+    assert_eq!(
+        elf_map.elves,
+        ElfMap::parser(
+            r"..............
+.......#......
+.....#...#....
+...#..#.#.....
+.......#..#...
+....#.#.##....
+..#..#.#......
+..#.#.#.##....
+..............
+....#..#......
+..............
+..............
+"
+        )
+        .unwrap()
+        .1
+        .elves
+    );
+
+    elf_map.process_round();
+    assert_eq!(
+        elf_map.elves,
+        ElfMap::parser(
+            r"..............
+.......#......
+....#.....#...
+...#..#.#.....
+.......#...#..
+...#..#.#.....
+.#...#.#.#....
+..............
+..#.#.#.##....
+....#..#......
+..............
+..............
+"
+        )
+        .unwrap()
+        .1
+        .elves
+    );
+
+    elf_map.process_round();
+    assert_eq!(
+        elf_map.elves,
+        ElfMap::parser(
+            r"..............
+.......#......
+.....#....#...
+..#..#...#....
+.......#...#..
+...#..#.#.....
+.#..#.....#...
+.......##.....
+..##.#....#...
+...#..........
+.......#......
+.............."
+        )
+        .unwrap()
+        .1
+        .elves
+    );
+
+    elf_map.process_round();
+    assert_eq!(
+        elf_map.elves,
+        ElfMap::parser(
+            r"..............
+.......#......
+......#....#..
+..#...##......
+...#.....#.#..
+.........#....
+.#...###..#...
+..#......#....
+....##....#...
+....#.........
+.......#......
+.............."
+        )
+        .unwrap()
+        .1
+        .elves
+    );
+
+    elf_map.process_round();
+    assert_eq!(
+        elf_map.elves,
+        ElfMap::parser(
+            r".......#......
+..............
+..#..#.....#..
+.........#....
+......##...#..
+.#.#.####.....
+...........#..
+....##..#.....
+..#...........
+..........#...
+....#..#......
+.............."
+        )
+        .unwrap()
+        .1
+        .elves
+    );
+
+    for _ in 0..5 {
+        elf_map.process_round();
+    }
+    assert_eq!(
+        elf_map.elves,
+        ElfMap::parser(
+            r".......#......
+...........#..
+..#.#..#......
+......#.......
+...#.....#..#.
+.#......##....
+.....##.......
+..#........#..
+....#.#..#....
+..............
+....#..#..#...
+.............."
+        )
+        .unwrap()
+        .1
+        .elves
+    );
+}