day 8 pt1

data/examples/08.txt

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

src/bin/08.rs

@@ -0,0 +1,87 @@
+use std::collections::HashMap;
+
+use itertools::Itertools;
+
+advent_of_code::solution!(8);
+
+pub fn part_one(input: &str) -> Option<u32> {
+    let mut grid_size: (u32, u32) = (input.lines().count() as u32, 0);
+
+    let mut antennas: HashMap<char, Vec<(u32, u32)>> = HashMap::new();
+
+    for (row_idx, line) in input.lines().enumerate() {
+        if row_idx == 0 { grid_size.1 = line.chars().count() as u32; }
+
+        for (col_idx, c) in line.chars().enumerate(){
+            if c != '.' {
+                if antennas.contains_key(&c) {
+                    antennas.entry(c).and_modify(|v| v.push((row_idx as u32, col_idx as u32)));
+                } else {
+                    antennas.insert(c, vec![(row_idx as u32, col_idx as u32)]);
+                }
+            }
+        }
+    }
+
+    // let locations = HashSet::new();
+
+    let locations = antennas.iter().flat_map(|(_key, values)| {
+        // println!("GROUP {} VALUE {:?}", _key, values);
+
+        values.iter().permutations(2).flat_map(|points| {
+            assert_eq!(points.len(), 2);
+            get_antinodes(points[0], points[1], grid_size)
+        }).unique().collect_vec()
+    }).unique();
+
+    // println!("ALL LOCATIONS: {:?}", locations.clone().collect_vec());
+
+    Some(locations.count() as u32)
+}
+
+pub fn part_two(input: &str) -> Option<u32> {
+    None
+}
+
+fn get_antinodes(p1: &(u32, u32), p2: &(u32, u32), grid_size: (u32, u32)) -> Vec<(u32, u32)> {
+    let diff = (p1.0 as isize - p2.0 as isize, p1.1 as isize - p2.1 as isize);
+
+    let a1 = (p1.0 as isize + diff.0, p1.1 as isize + diff.1);
+    let a2 = (p2.0 as isize - diff.0, p2.1 as isize - diff.1);
+
+    let is_valid = |p: (isize, isize)| (0..grid_size.0 as isize).contains(&p.0) && (0..grid_size.1 as isize).contains(&p.1);
+
+    let mut results = vec![];
+
+    if is_valid(a1) { results.push((a1.0 as u32, a1.1 as u32)) };
+    if is_valid(a2) { results.push((a2.0 as u32, a2.1 as u32)) };
+
+    results
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_get_antinodes() {
+        let p1 = (5, 6);
+        let p2 = (8, 8);
+        let grid_size = (12, 12);
+
+        let result = get_antinodes(&p1, &p2, grid_size);
+        assert_eq!(result, vec![(2, 4), (11, 10)]);
+    }
+
+    #[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, None);
+    }
+}