day11 part 1

2023/day11/src/lib.rs

@@ -0,0 +1,131 @@
+use std::fmt::Debug;
+
+use helper::{Day, IteratorExt, Variants};
+
+pub fn main() {
+    helper::main::<Day11>(include_str!("../input.txt"));
+}
+
+struct Day11;
+
+helper::define_variants! {
+    day => crate::Day11;
+    part1 {
+        basic => crate::part1;
+    }
+    part2 {
+        basic => crate::part2;
+    }
+}
+
+impl Day for Day11 {
+    fn part1() -> Variants {
+        part1_variants!(construct_variants)
+    }
+
+    fn part2() -> Variants {
+        part2_variants!(construct_variants)
+    }
+}
+
+struct Universe {
+    rows: Vec<Vec<bool>>,
+}
+
+impl Debug for Universe {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        writeln!(f)?;
+        for row in &self.rows {
+            for &col in row {
+                write!(f, "{}", if col { '#' } else { '.' })?;
+            }
+            writeln!(f)?;
+        }
+        Ok(())
+    }
+}
+
+fn parse(input: &str) -> Universe {
+    Universe {
+        rows: input
+            .lines()
+            .map(|line| line.chars().map(|c| c == '#').collect_vec())
+            .collect_vec(),
+    }
+}
+
+fn expand(universe: Universe) -> Universe {
+    let mut rows = universe
+        .rows
+        .into_iter()
+        .flat_map(|row| {
+            if row.iter().all(|b| !b) {
+                vec![row.clone(), row]
+            } else {
+                vec![row]
+            }
+        })
+        .collect_vec();
+
+    let mut col = 0;
+    while col < rows[0].len() {
+        if rows.iter().all(|row| !row[col]) {
+            rows.iter_mut().for_each(|row| row.insert(col, false));
+            col += 1;
+        }
+        col += 1;
+    }
+
+    Universe { rows }
+}
+
+fn part1(input: &str) -> u64 {
+    let universe = parse(input);
+    let universe = expand(universe);
+
+    let galaxies = universe
+        .rows
+        .iter()
+        .enumerate()
+        .flat_map(|(i, row)| {
+            row.iter()
+                .copied()
+                .enumerate()
+                .filter(|&(_, b)| b)
+                .map(move |(j, _)| (i, j))
+        })
+        .collect_vec();
+
+    let mut sum = 0;
+
+    for i in 0..galaxies.len() {
+        for j in (i + 1)..galaxies.len() {
+            let lhs = galaxies[i];
+            let rhs = galaxies[j];
+
+            let distance_x = ((lhs.1 as i64) - (rhs.1 as i64)).abs();
+            let distance_y = ((lhs.0 as i64) - (rhs.0 as i64)).abs();
+
+            sum += distance_x + distance_y;
+        }
+    }
+
+    sum as u64
+}
+
+fn part2(_input: &str) -> u64 {
+    0
+}
+
+helper::tests! {
+    day11 Day11;
+    part1 {
+        small => 374;
+        default => 0;
+    }
+    part2 {
+        small => 0;
+        default => 0;
+    }
+}
+helper::benchmarks! {}