add initial data

aoc11/Cargo.lock

@@ -0,0 +1,7 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 3
+
+[[package]]
+name = "aoc11"
+version = "0.1.0"

aoc11/Cargo.toml

@@ -0,0 +1,8 @@
+[package]
+name = "aoc11"
+version = "0.1.0"
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]

aoc11/example.txt

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+5483143223
+2745854711
+5264556173
+6141336146
+6357385478
+4167524645
+2176841721
+6882881134
+4846848554
+5283751526

aoc11/input.txt

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+4112256372
+3143253712
+4516848631
+3783477137
+3746723582
+5861358884
+4843351774
+2316447621
+6643817745
+6366815868

aoc11/src/main.rs

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+use std::{collections::HashSet, fs};
+
+const NEIGHBOUR_INDICES: [isize; 3] = [-1, 0, 1];
+
+struct Grid {
+    data: Vec<Vec<u32>>,
+    nx: usize,
+    ny: usize,
+    flashes: usize,
+}
+
+impl Grid {
+    fn from_file(filename: &str) -> Self {
+        let data: Vec<Vec<_>> = fs::read_to_string(filename)
+            .unwrap()
+            .split_whitespace()
+            .map(|line| line.chars().map(|c| c.to_digit(10).unwrap()).collect())
+            .collect();
+        let nx = data[0].len();
+        let ny = data.len();
+        let flashes = 0;
+        Grid {
+            data,
+            nx,
+            ny,
+            flashes,
+        }
+    }
+
+    fn iterate(&mut self) {
+        self.increment_all_by_one();
+        self.flash_where_level_above_nine();
+        self.reset_flashed();
+    }
+
+    fn print(&self) {
+        for y in 0..self.ny {
+            for x in 0..self.nx {
+                let val = self.data[y][x];
+                if val > 9 {
+                    print!(".");
+                } else {
+                    print!("{}", val);
+                }
+            }
+            println!();
+        }
+    }
+
+    fn reset_flashed(&mut self) {
+        for y in 0..self.ny {
+            for x in 0..self.nx {
+                if self.data[y][x] > 9 {
+                    self.data[y][x] = 0;
+                }
+            }
+        }
+    }
+
+    fn increment_all_by_one(&mut self) {
+        for y in 0..self.ny {
+            for x in 0..self.nx {
+                self.data[y][x] += 1;
+            }
+        }
+    }
+
+    #[allow(clippy::all)]
+    fn flash_where_level_above_nine(&mut self) {
+        let mut have_flashed = HashSet::new();
+        loop {
+            let mut increased = 0;
+            for y in 0..self.ny {
+                for x in 0..self.nx {
+                    if self.data[y][x] > 9 && !have_flashed.contains(&(y, x)) {
+                        have_flashed.insert((y, x));
+                        self.flashes += 1;
+                        increased += self.increase_neighbors_by_one(&x, &y);
+                    }
+                }
+            }
+            if increased == 0 {
+                break;
+            }
+        }
+    }
+
+    fn increase_neighbors_by_one(&mut self, x: &usize, y: &usize) -> i32 {
+        let mut increased = 0;
+        for (ox, oy) in self.get_neighbours(x, y) {
+            self.data[oy][ox] += 1;
+            increased += 1;
+        }
+        increased
+    }
+
+    fn get_neighbours(&self, x: &usize, y: &usize) -> Vec<(usize, usize)> {
+        let mut result = vec![];
+        for dx in NEIGHBOUR_INDICES {
+            for dy in NEIGHBOUR_INDICES {
+                let ox = (*x as isize) + dx;
+                let oy = (*y as isize) + dy;
+                if ox < 0
+                    || oy < 0
+                    || ox >= self.nx as isize
+                    || oy >= self.ny as isize
+                    || (dx == 0 && dy == 0)
+                {
+                    continue;
+                }
+                result.push((ox as usize, oy as usize));
+            }
+        }
+        result
+    }
+}
+
+fn main() {
+    let mut grid = Grid::from_file("input.txt");
+    grid.print();
+    println!();
+
+    let mut i = 0;
+    for _ in 0..100 {
+        grid.iterate();
+        i += 1;
+    }
+
+    grid.print();
+    println!();
+    println!("{}", grid.flashes);
+
+    loop {
+        let before = grid.flashes;
+        grid.iterate();
+        let after = grid.flashes;
+        i += 1;
+        if after - before == grid.nx * grid.ny {
+            println!();
+            println!("{i}");
+            break;
+        }
+    }
+}
+
+#[cfg(test)]
+mod test {
+    use crate::Grid;
+    #[test]
+    fn get_neighbours() {
+        let data = vec![
+            vec![1, 1, 1, 1],
+            vec![1, 1, 1, 1],
+            vec![1, 1, 1, 1],
+            vec![1, 1, 1, 1],
+        ];
+        let nx = 4;
+        let ny = 4;
+        let grid = Grid {
+            data,
+            nx,
+            ny,
+            flashes: 0,
+        };
+        println!("{:?}\n", grid.get_neighbours(&1, &1));
+        println!("{:?}\n", grid.get_neighbours(&2, &2));
+        println!("{:?}\n", grid.get_neighbours(&0, &0));
+    }
+}