day 14 part 1

src/day14.rs

@@ -0,0 +1,106 @@
+use std::fs::read_to_string;
+
+use itertools::Itertools;
+
+pub fn day_main() {
+    let input = read_to_string("input/day14.txt").unwrap();
+    let input = input.trim();
+    println!(" part1: {}", part1(input)); // 50112000 too low
+    println!(" part2: {}", part2(input));
+}
+
+type RiddleResult = usize;
+
+fn part1(input: &str) -> RiddleResult {
+    solve(input, 100, 101, 103)
+}
+
+fn solve(input: &str, rounds: i64, width: i64, height: i64) -> RiddleResult {
+    let mut robots: Vec<((i64, i64), (i64, i64))> = input
+        .lines()
+        .map(|line| {
+            line.strip_prefix("p=")
+                .unwrap()
+                .split(" v=")
+                .map(|s| {
+                    s.split(",")
+                        .map(|d| d.parse::<i64>().unwrap())
+                        .collect_tuple::<(i64, i64)>()
+                        .unwrap()
+                })
+                .collect_tuple()
+                .unwrap()
+        })
+        .collect_vec();
+    for _ in 0..rounds {
+        robots.iter_mut().for_each(|((px, py), (vx, vy))| {
+            *px = (*px + width + *vx) % width;
+            *py = (*py + height + *vy) % height;
+        });
+    }
+    // for y in 0..height {
+    //     for x in 0..width {
+    //         let c = robots
+    //             .iter()
+    //             .filter(|&&((px, py), _)| px == x && py == y)
+    //             .count();
+    //         if c == 0 {
+    //             print!(".");
+    //         } else {
+    //             print!("{c}");
+    //         }
+    //     }
+    //     println!();
+    // }
+    robots
+        .iter()
+        .filter(|&&((px, py), _)| px < width / 2 && py < height / 2)
+        .count()
+        * robots
+            .iter()
+            .filter(|&&((px, py), _)| px < width / 2 && py > height / 2)
+            .count()
+        * robots
+            .iter()
+            .filter(|&&((px, py), _)| px > width / 2 && py < height / 2)
+            .count()
+        * robots
+            .iter()
+            .filter(|&&((px, py), _)| px > width / 2 && py > height / 2)
+            .count()
+}
+
+fn part2(_input: &str) -> RiddleResult {
+    0
+}
+
+#[cfg(test)]
+mod test {
+    use crate::day14::solve;
+
+    use super::part2;
+
+    const TEST_INPUT: &str = r"p=0,4 v=3,-3
+p=6,3 v=-1,-3
+p=10,3 v=-1,2
+p=2,0 v=2,-1
+p=0,0 v=1,3
+p=3,0 v=-2,-2
+p=7,6 v=-1,-3
+p=3,0 v=-1,-2
+p=9,3 v=2,3
+p=7,3 v=-1,2
+p=2,4 v=2,-3
+p=9,5 v=-3,-3
+";
+
+    #[test]
+    fn test1() {
+        assert_eq!(solve(TEST_INPUT, 100, 11, 7), 12);
+    }
+
+    #[test]
+    fn test2() {
+        assert_eq!(part2(TEST_INPUT), 0);
+    }
+}

src/lib.rs

@@ -11,5 +11,6 @@ pub mod day10;
 pub mod day11;
 pub mod day12;
 pub mod day13;
+pub mod day14;
 // PLACEHOLDER
 pub mod utils;

src/main.rs

@@ -18,6 +18,7 @@ fn main() {
         (11, day11::day_main),
         (12, day12::day_main),
         (13, day13::day_main),
+        (14, day14::day_main),
         // PLACEHOLDER
     ]);
     let day: Option<u8> = args().nth(1).and_then(|a| a.parse().ok());