Day08 - part 1

diff --git a/src/day08.rs b/src/day08.rs
new file mode 100644 (file)
index 0000000..67a69da
--- /dev/null
+++ b/src/day08.rs
@@ -0,0 +1,105 @@
+use std::error::Error;
+use std::path::Path;
+use std::collections::{HashMap, HashSet};
+
+struct Puzzle {
+    map: HashMap<(isize, isize), char>,
+}
+
+impl Puzzle {
+    pub fn new(input: &str) -> Self {
+        let mut map = HashMap::new();
+        input.lines()
+            .enumerate()
+            .for_each(|(row, l)| {
+                l.chars()
+                    .enumerate()
+                    .for_each(|(col, c)| {
+                        map.insert((row as isize, col as isize), c);
+                    });
+            });
+        Self { map }
+    }
+}
+
+fn run_part1(input: &str) -> Result<u32, Box<dyn Error>> {
+    println!("Running {} - part 1", get_day());
+
+    let puzzle = Puzzle::new(input);
+    let mut visited: HashSet<(isize, isize)> = HashSet::new();
+    let mut antinodes: HashSet<(isize, isize)> = HashSet::new();
+
+    puzzle.map.iter()
+        .filter(|(_, value)| **value != '.')
+        .for_each(|(key, value)| {
+            if !visited.contains(key) {
+                visited.insert(*key);
+
+                puzzle.map.iter()
+                    .filter(|(k, v)| *v == value && *k != key)
+                    .for_each(|(k, v)| {
+                        let x1 = if k <= key { k } else { key };
+                        let x2 = if k <= key { key } else { k };
+                        let d = (x1.0 - x2.0, x1.1 - x2.1);
+                        for a in [(x1.0 + d.0, x1.1 + d.1), (x2.0 - d.0, x2.1 - d.1)] {
+                            if puzzle.map.contains_key(&a) {
+                                antinodes.insert(a);
+                            }
+                        }
+                    });
+            }
+        });
+
+    let res = antinodes.len() as u32;
+    Ok(res)
+}
+
+fn run_part2(input: &str) -> Result<u32, Box<dyn Error>> {
+    println!("Running {} - part 2", get_day());
+
+    Ok(0)
+}
+
+pub fn run(input: &str) -> Result<(), Box<dyn Error>> {
+    let res = run_part1(&input)?;
+    println!("{res}");
+
+    let res = run_part2(&input)?;
+    println!("{res}");
+
+    Ok(())
+}
+
+fn get_day() -> String {
+    let filename = file!();
+    Path::new(filename).file_stem().unwrap().to_str().unwrap().to_string()
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    static TEXT_INPUT: &str = "\
+............
+........0...
+.....0......
+.......0....
+....0.......
+......A.....
+............
+............
+........A...
+.........A..
+............
+............";
+
+    #[test]
+    fn test_part1() {
+        assert_eq!(14, run_part1(TEXT_INPUT).unwrap());
+    }
+
+    #[test]
+    fn test_part2() {
+        assert_eq!(0, run_part2(TEXT_INPUT).unwrap());
+    }
+}

diff --git a/src/main.rs b/src/main.rs
index a3058a07cd5e9b9b32c0b55302097ae76962d58c..d3f9981757c9ab631aeb9350dd3a3e73606e9aac 100644 (file)
--- a/src/main.rs
+++ b/src/main.rs
@@ -11,6 +11,7 @@ pub mod day04;
 pub mod day05;
 pub mod day06;
 pub mod day07;
+pub mod day08;
 
 fn main() {
     let args: Vec<String> = env::args().collect();
@@ -40,6 +41,7 @@ fn run(day: &str, input_file: &str) -> Result<(), Box<dyn Error>> {
         "day05" => day05::run(&input)?,
         "day06" => day06::run(&input)?,
         "day07" => day07::run(&input)?,
+        "day08" => day08::run(&input)?,
         _ => return Err(format!("unknown or unimplemented day \"{day}\"").into()),
     }
     Ok(())