feat: day 8

README.md

@@ -30,8 +30,9 @@ Solutions for [Advent of Code](https://adventofcode.com/) in [Rust](https://www.
 | [Day 5](./src/bin/05.rs) | `1.8ms` | `48.4ms` |
 | [Day 6](./src/bin/06.rs) | `1.1ms` | `642.9ms` |
 | [Day 7](./src/bin/07.rs) | `4.8ms` | `254.2ms` |
+| [Day 8](./src/bin/08.rs) | `89.8µs` | `253.6µs` |
 
-**Total: 965.96ms**
+**Total: 966.31ms**
 <!--- benchmarking table --->
 
 ---

data/examples/08.txt

@@ -0,0 +1,12 @@
+............
+........0...
+.....0......
+.......0....
+....0.......
+......A.....
+............
+............
+........A...
+.........A..
+............
+............

src/bin/08.rs

@@ -0,0 +1,74 @@
+use std::{collections::HashSet, ops::RangeBounds};
+
+advent_of_code::solution!(8);
+
+fn in_bounds(map: &Vec<Vec<char>>, pos: (i32, i32)) -> bool {
+    pos.0 >= 0 && pos.1 >= 0 && pos.0 < map.len() as i32 && pos.1 < map[0].len() as i32
+}
+
+pub fn solve<R: RangeBounds<i32> + IntoIterator<Item = i32> + Clone>(
+    input: &str,
+    range: R,
+) -> Option<u32> {
+    let map: Vec<Vec<char>> = input.lines().map(|line| line.chars().collect()).collect();
+    let mut antennas: Vec<((usize, usize), char)> = Vec::new();
+    for i in 0..map.len() {
+        for j in 0..map[i].len() {
+            if map[i][j] != '.' {
+                antennas.push(((i, j), map[i][j]));
+            }
+        }
+    }
+    let mut nodes: HashSet<(usize, usize)> = HashSet::new();
+    antennas.iter().for_each(|a| {
+        antennas.iter().filter(|b| a.1 == b.1).for_each(|b| {
+            if a.0 != b.0 {
+                let (y1, x1) = a.0;
+                let (y2, x2) = b.0;
+                let (dx, dy) = (x2 as i32 - x1 as i32, y2 as i32 - y1 as i32);
+                for k in range.clone() {
+                    let (ny1, nx1) = (y1 as i32 - dy * k, x1 as i32 - dx * k);
+                    if in_bounds(&map, (ny1, nx1)) {
+                        nodes.insert((ny1 as usize, nx1 as usize));
+                    } else {
+                        break;
+                    }
+                }
+                for k in range.clone() {
+                    let (ny2, nx2) = (y2 as i32 + dy * k, x2 as i32 + dx * k);
+                    if in_bounds(&map, (ny2, nx2)) {
+                        nodes.insert((ny2 as usize, nx2 as usize));
+                    } else {
+                        break;
+                    }
+                }
+            }
+        });
+    });
+    Some(nodes.len() as u32)
+}
+
+pub fn part_one(input: &str) -> Option<u32> {
+    solve(input, 1..=1)
+}
+
+pub fn part_two(input: &str) -> Option<u32> {
+    solve(input, 0..)
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_part_one() {
+        let result = part_one(&advent_of_code::template::read_file("examples", DAY));
+        assert_eq!(result, Some(14));
+    }
+
+    #[test]
+    fn test_part_two() {
+        let result = part_two(&advent_of_code::template::read_file("examples", DAY));
+        assert_eq!(result, Some(34));
+    }
+}