day 23

Cargo.lock

@@ -7,6 +7,7 @@ name = "aoc2022"
 version = "0.1.0"
 dependencies = [
  "bitvec",
+ "derive_more",
  "itertools",
  "nom",
  "num",
@@ -39,6 +40,12 @@ version = "1.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "baf1de4339761588bc0619e3cbc0120ee582ebb74b53b4efbf79117bd2da40fd"
 
+[[package]]
+name = "convert_case"
+version = "0.4.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6245d59a3e82a7fc217c5828a6692dbc6dfb63a0c8c90495621f7b9d79704a0e"
+
 [[package]]
 name = "crossbeam-channel"
 version = "0.5.6"
@@ -82,6 +89,19 @@ dependencies = [
  "cfg-if",
 ]
 
+[[package]]
+name = "derive_more"
+version = "0.99.17"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4fb810d30a7c1953f91334de7244731fc3f3c10d7fe163338a35b9f640960321"
+dependencies = [
+ "convert_case",
+ "proc-macro2",
+ "quote",
+ "rustc_version",
+ "syn",
+]
+
 [[package]]
 name = "either"
 version = "1.8.0"
@@ -267,6 +287,24 @@ dependencies = [
  "indexmap",
 ]
 
+[[package]]
+name = "proc-macro2"
+version = "1.0.49"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "57a8eca9f9c4ffde41714334dee777596264c7825420f521abc92b5b5deb63a5"
+dependencies = [
+ "unicode-ident",
+]
+
+[[package]]
+name = "quote"
+version = "1.0.23"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8856d8364d252a14d474036ea1358d63c9e6965c8e5c1885c18f73d70bff9c7b"
+dependencies = [
+ "proc-macro2",
+]
+
 [[package]]
 name = "radium"
 version = "0.7.0"
@@ -295,24 +333,56 @@ dependencies = [
  "num_cpus",
 ]
 
+[[package]]
+name = "rustc_version"
+version = "0.4.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "bfa0f585226d2e68097d4f95d113b15b83a82e819ab25717ec0590d9584ef366"
+dependencies = [
+ "semver",
+]
+
 [[package]]
 name = "scopeguard"
 version = "1.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "d29ab0c6d3fc0ee92fe66e2d99f700eab17a8d57d1c1d3b748380fb20baa78cd"
 
+[[package]]
+name = "semver"
+version = "1.0.16"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "58bc9567378fc7690d6b2addae4e60ac2eeea07becb2c64b9f218b53865cba2a"
+
 [[package]]
 name = "smallvec"
 version = "0.2.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "4c8cbcd6df1e117c2210e13ab5109635ad68a929fcbb8964dc965b76cb5ee013"
 
+[[package]]
+name = "syn"
+version = "1.0.107"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1f4064b5b16e03ae50984a5a8ed5d4f8803e6bc1fd170a3cda91a1be4b18e3f5"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "unicode-ident",
+]
+
 [[package]]
 name = "tap"
 version = "1.0.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "55937e1799185b12863d447f42597ed69d9928686b8d88a1df17376a097d8369"
 
+[[package]]
+name = "unicode-ident"
+version = "1.0.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "84a22b9f218b40614adcb3f4ff08b703773ad44fa9423e4e0d346d5db86e4ebc"
+
 [[package]]
 name = "wyz"
 version = "0.5.1"

Cargo.toml

@@ -7,6 +7,7 @@ edition = "2021"
 
 [dependencies]
 bitvec = "1.0.1"
+derive_more = "0.99.17"
 itertools = "0.10.5"
 nom = "7.1.1"
 num = "0.4.0"

inputs/day23.txt

@@ -0,0 +1,71 @@
+...####..#.#.#....###..#....#..#..#...##..###..##.#...######.##....####
+..#.##..#.#...###..###.##....#..##......#.###..###....#.#.#....#...#.#.
+.##...#...####..####....#....#####.##.#.....#.#.#.#..#..#...####....###
+.####..#.##...#.##..#.#...#..#..##.######.#######.###.##.....####.#.##.
+##.##.#..######.####..##...##.#.##...###.###..#.#..####..##...###.##.#.
+...###.#.###..####..###.##..#..###..#..##.###.##.##....##...##.#.#..##.
+###.##...#...#.#..####..##.#..###.##..#..##.#...#...##..##..##.##.###.#
+..##....###.##.#...#####.#.#.###.#.#.#.##.#...#####.#####.....###.....#
+#.####.#...#.#...##..#..#.#...###.#.####.#..##..##.#.###...#.####....##
+#.##...#.#####...##....##..###..#...##.###..#.#.##.##.....#####....#...
+#...#..#..#.#...##..#####.#.###......##..##.##.##...###..###...#..###..
+..#.##.#..##.##.####.....#.###..#..#..#...###.###..#.#.##.##..#####..##
+.##.#...#.....####......#.#..#..#.#....#.#...####...##.#.#.....#.#.....
+#..#.##..###..#.....#.###..#.#..........##.......##.##.#..######...###.
+.#...##.#.#...##.####..######.###.#.#.#.####.##.###..#...###.#..#..##.#
+#.#.##.#.###..##.###.##.....###.#.#...#...###.##.#.#.##.##.#####.....#.
+.#...###.##...#.##.#.###.###.##......##...##.#.###..#..#.#.##...####.#.
+.#.#.##..#...#.##..#..##.....#....#....#.###....#########..#.#.########
+.#.##..###..##..#.......##.##..#..###.#.##.####....#..#.#...##..##.#...
+#####.##.#.....#.##...#.#...#.#.####..####....#.#...#.....###...##.....
+..###....#....##...#.#...###....##.###.#.#...##..##.#..#.##....#.#.#.##
+########..####...#.#..##.###...##.#...#...#.######...#..#..#..#...#..##
+#.#....##...##..#...#....#.##....#.###.##.#...###.#..#.#.#...###..#.#.#
+#.##........#..##...#...##.##.###.#.##...##...#####.#.#.....####.#.#..#
+##.##...####.##.#...#....#...###.#...#....#.#.#.####...#.#....#.####.#.
+.###....#..#.#..#..####..###.#.#..#.#..#.####..#####..#.#.#..#.....##.#
+.#####.#.##.###......#..##.#.....#######..##.##.#####....#..#.#..####.#
+.#....###....#.##..##.#.#.#.....#####..#.#.#.##...#.#....#.##..##....#.
+####....####...#.#...#..##....#.#.#.###..#.######.##..##..######...#.#.
+.#..####..#####.###..#..##.#.####.##.##..#.###..#...##.#...#.#.#.#.#.##
+#.###########.####.....###.#..#...###.#######...#.#...##..###....#....#
+#..#.####...###..####.#.##.#.#.#.#####.###.####...#...#....########..#.
+#######.#..#.#..####.##.##..##.#...##..#######..#.#..#...#..##..#.###.#
+##.#.....###.#..####.##..#.#######.#.#..#.##.#..###.##..##.##.#...#.#.#
+#.#######.#.##.#.###.##.##...##..#.#....#.#.#..#.#..###..##.#.#.....##.
+.##.##.#...####.#####.####.####.....#..####..#..##..###...#.#.###.#...#
+.####...#..#.#.#.#........#..###...#####..####..##..######.###...#####.
+###....#..##.##..#####....##.#..#...##.#####..#..###.#####..###.#..##.#
+..#.#...#.##..#.##.####.####..#######....##....#.#....#.#.#..##.#.#..##
+.#..#.########.........###.#.....###.######..#.######...####..#..#.#.##
+.#.#...###...#.#.#.#..#...##.###.#.#.##.##.....####......##.#.#....##.#
+..##..##...#.#######.#.##.####.###.#..#.....#.#..#...#..####..##..#.###
+.#...####.##....###..#.###...###.##...###..######.#.#.#.#.#.#.#....#.##
+.###..#.###.###..##.#..##..#.#.#...#..#.#..#...##..#..#...###...#####.#
+#.#..#.#.#.....##..#.##..##.#.....#..###..#.#.#.#.#.#.##..#.####..##...
+..#.#.####...#.##..##.##.####..##.#.#..##.#.###.#.######..#.######.#...
+###.#.#.#.####..##.######.#.#...##......###..###.#..#...#...#.#..######
+.###.#..#..######..##.####.###..##.#...#.#.#......###..##.#.#....#.#.#.
+.##..#...#....#..###.##.#..#####.#.#....######..#....#..######.....#...
+#.#...#..#.##...#..#..###.......####...#.####...#.#.#....#####.##...#.#
+....#.####.#...#..#####.#..###..######.###.....#..#.#.#.#.#.##.#.##....
+#.......#####.#.###..##.###..#####..#.###..#.....#.###.###..###..#.##.#
+##.#.#....##.#.#..#..#...###.#..#.....###...###...#..#.######.#.#...##.
+#....####.##.###....#....#....#...#..####...#.#.#.###..##.#.#..##.#..##
+#.....#.##....###..####..##.#.......#..#.#.#.....#....####.#...#....###
+###.#..####....#.....#..####....######.....#.#....#..###.#.#..#.#..###.
+#..#.#.#...##....##.##....##.....#..####.###..##.#.#.##..#.##.###...###
+....###.#.#.#..###.#.##.#.#.#.#####.#####..#..##...##.##.#...####.#.###
+#####.....#.#.#.#.#.#.###.#####.#...#.##..#.#.##..##..###...#...#..##..
+##.####.#.#.##..##.##.###....##.#..###.####..#######.#...##....#..##.##
+##..#.####.##..#..#.#.#####.#.#.....#####..##..#.##.....##..#.#....##.#
+.#..####...####.#####.##..#.##.....###.###.#.#.######..####.#...#..#.#.
+##.####..##..#.....##.#.####..#..#....##...#....#####..##########.###.#
+#...#.#.....#####.......###.#.#.#.###....#.#..#..#.##..#..#..#.####.###
+##.###..#..##......##########....###..#######..#....#.#..###.##........
+####.........#.#...##.#.#.#..#.#.####.#####....##...#.#.##.###..#.##.##
+.####.#...#..#.##.####..##..#..#...##...........##..###.####..##..#.#..
+.#####.##....##.#..####.##..##.#.###.....##.#..#..#.#.#...#.#...####...
+#...####........#.##.####..##.....#####.#.#####.#####..#.##.#..##...##.
+.###..###.####..###..##..##.#..##.###.#...#..#...#..#...#..#######.#.##
+.#..#..##...##....##....####..#....#.##.....#.##..#.#..#...#..##.#..#.#

src/bin/day23_1.rs

@@ -0,0 +1,8 @@
+use std::fs;
+
+use aoc2022::day23::process_part_1;
+
+fn main() {
+    let file = fs::read_to_string("./inputs/day23.txt").unwrap();
+    println!("{}", process_part_1(&file));
+}

src/bin/day23_2.rs

@@ -0,0 +1,8 @@
+use std::fs;
+
+use aoc2022::day23::process_part_2;
+
+fn main() {
+    let file = fs::read_to_string("./inputs/day23.txt").unwrap();
+    println!("{}", process_part_2(&file));
+}

src/day23.rs

@@ -1,24 +1,180 @@
-pub fn process_part_1(_input: &str) -> u32 {
+use std::collections::BTreeSet;
-    0
+use std::fmt::{Display, Formatter};
+
+use derive_more::{Add, Sub};
+use itertools::Itertools;
+use itertools::MinMaxResult::MinMax;
+use nom::character::complete::{newline, one_of};
+use nom::multi::{many1, separated_list1};
+use nom::IResult;
+
+#[derive(Debug, Clone, Copy, Default, Eq, PartialEq, Ord, PartialOrd, Hash, Add, Sub)]
+struct Vec2 {
+    x: i64,
+    y: i64,
+}
+impl Display for Vec2 {
+    fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
+        write!(f, "({}, {})", self.x, self.y)
+    }
 }
 
-pub fn process_part_2(_input: &str) -> u32 {
+impl From<(usize, usize)> for Vec2 {
-    0
+    fn from(value: (usize, usize)) -> Self {
+        Self {
+            x: value.0 as i64,
+            y: value.1 as i64,
+        }
+    }
+}
+
+// didn't wanna write them myself
+macro_rules! vec2 {
+    ($x:expr,$y:expr) => {
+        Vec2 { x: $x, y: $y }
+    };
+}
+
+const DIRECTIONS: [[Vec2; 3]; 4] = [
+    [vec2!(-1, -1), vec2!(0, -1), vec2!(1, -1)], // North: NW, N, NE
+    [vec2!(-1, 1), vec2!(0, 1), vec2!(1, 1)],    // South: SW, S, SE
+    [vec2!(-1, -1), vec2!(-1, 0), vec2!(-1, 1)], // West:  NW, W, SW
+    [vec2!(1, -1), vec2!(1, 0), vec2!(1, 1)],    // East:  NE, E, SE
+];
+
+pub fn process_part_1(input: &str) -> usize {
+    let mut elves = parse_input(input).unwrap().1;
+    for i in 0..10 {
+        elves.step(i);
+    }
+    elves.bounding_box_area() - elves.0.len()
+}
+
+pub fn process_part_2(input: &str) -> usize {
+    let mut elves = parse_input(input).unwrap().1;
+    (0..)
+        .take_while(|i| elves.step(*i))
+        .last()
+        .map(|x| x + 2) // we start counting at 0 while aoc expects 1, and take_while 'noms' the one we need to keep away
+        .unwrap_or(0)
+}
+
+fn parse_input(input: &str) -> IResult<&str, Elves> {
+    let (input, items) = separated_list1(newline, many1(one_of(".#")))(input)?;
+    let result = items
+        .iter()
+        .enumerate()
+        .flat_map(|(y, row)| {
+            row.iter()
+                .enumerate()
+                .flat_map(move |(x, &elem)| match elem {
+                    '#' => Some(Vec2::from((x, y))),
+                    _ => None,
+                })
+        })
+        .collect();
+    Ok((input, Elves(result)))
+}
+
+#[derive(Debug)]
+struct Elves(BTreeSet<Vec2>);
+
+impl Elves {
+    fn step(&mut self, dir_counter: usize) -> bool {
+        let mut desired_moves = Vec::new();
+        let mut has_moved = false;
+        for elf in self.0.iter() {
+            if !self.has_elf_near(*elf) {
+                continue;
+            }
+
+            for i in 0..4 {
+                let offsets = DIRECTIONS[(dir_counter + i) % 4];
+                if !self.has_elf(*elf, &offsets) {
+                    let next = *elf + offsets[1];
+                    desired_moves.push((next, *elf));
+                    break;
+                }
+            }
+        }
+        let moves = desired_moves
+            .into_iter()
+            .sorted_unstable_by(|a, b| a.0.cmp(&b.0))
+            .dedup_by_with_count(|a, b| a.0 == b.0)
+            .filter(|(count, _)| *count == 1)
+            .map(|(_, m)| m);
+        for (next, elf) in moves {
+            self.0.remove(&elf);
+            self.0.insert(next);
+            has_moved = true;
+        }
+        has_moved
+    }
+
+    fn has_elf_near(&self, pos: Vec2) -> bool {
+        DIRECTIONS
+            .iter()
+            .flatten()
+            .any(|d| self.0.contains(&(pos + *d)))
+    }
+
+    fn has_elf(&self, pos: Vec2, offsets: &[Vec2]) -> bool {
+        offsets.iter().any(|d| self.0.contains(&(pos + *d)))
+    }
+
+    fn bounding_box(&self) -> (Vec2, Vec2) {
+        let MinMax(min_x, max_x) = self.0.iter().minmax_by_key(|p| p.x) else {
+            panic!("no min/max x?");
+        };
+        let MinMax(min_y, max_y) = self.0.iter().minmax_by_key(|p| p.y) else {
+            panic!("no min/max y?");
+        };
+        (vec2!(min_x.x, min_y.y), vec2!(max_x.x, max_y.y))
+    }
+
+    fn bounding_box_area(&self) -> usize {
+        let (min, max) = self.bounding_box();
+        ((max.x - min.x + 1) * (max.y - min.y + 1)) as usize
+    }
+}
+
+impl Display for Elves {
+    fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
+        let (min, max) = self.bounding_box();
+        for y in min.y..=max.y {
+            for x in min.x..=max.x {
+                let elf = if self.0.contains(&vec2!(x, y)) {
+                    '#'
+                } else {
+                    '.'
+                };
+                write!(f, "{elf}")?;
+            }
+            writeln!(f)?;
+        }
+        Ok(())
+    }
 }
 
 #[cfg(test)]
 mod tests {
     use super::*;
 
-    const INPUT: &str = "";
+    const INPUT: &str = "....#..
+..###.#
+#...#.#
+.#...##
+#.###..
+##.#.##
+.#..#..";
 
     #[test]
     fn day1() {
-        assert_eq!(process_part_1(INPUT), 0);
+        assert_eq!(process_part_1(INPUT), 110);
     }
 
     #[test]
     fn day2() {
-        assert_eq!(process_part_2(INPUT), 0);
+        assert_eq!(process_part_2(INPUT), 20);
     }
 }