dag 14 aoc klaar, deel 2 gedaan met minimale safety factor

advent_of_code/2024/14/src/main.rs

@@ -0,0 +1,115 @@
+use nom::{
+    bytes::complete::tag,
+    character::complete::{i64, multispace1},
+    multi::separated_list1,
+    sequence::{preceded, separated_pair},
+    IResult,
+};
+
+fn parse(input: &str) -> IResult<&str, Vec<((i64, i64), (i64, i64))>> {
+    let (input, result) = separated_list1(
+        multispace1,
+        separated_pair(
+            separated_pair(preceded(tag("p="), i64), tag(","), i64),
+            tag(" v="),
+            separated_pair(i64, tag(","), i64),
+        ),
+    )(input)?;
+
+    Ok((input, result))
+}
+
+fn calc_pos(
+    start_pos: (i64, i64),
+    velocity: (i64, i64),
+    width: i64,
+    height: i64,
+    time: i64,
+) -> (i64, i64) {
+    let x = (start_pos.0 + velocity.0 * time).rem_euclid(width);
+    let y = (start_pos.1 + velocity.1 * time).rem_euclid(height);
+
+    (x, y)
+}
+
+fn solve_1(input: &str, width: i64, height: i64) -> i64 {
+    let (_, result) = parse(input).unwrap();
+
+    let (mut q1, mut q2, mut q3, mut q4) = (0, 0, 0, 0);
+    for (x_end, y_end) in result
+        .into_iter()
+        .map(|(pos, vel)| calc_pos(pos, vel, width, height, 100))
+    {
+        if x_end < width / 2 && y_end < height / 2 {
+            q1 += 1;
+        } else if x_end > width / 2 && y_end < height / 2 {
+            q2 += 1;
+        } else if x_end < width / 2 && y_end > height / 2 {
+            q3 += 1;
+        } else if x_end > width / 2 && y_end > height / 2 {
+            q4 += 1;
+        }
+    }
+
+    q1 * q2 * q3 * q4
+}
+
+fn solve_2(input: &str, width: i64, height: i64) -> i64 {
+    let (_, mut robots) = parse(input).unwrap();
+
+    let mut min_e = i64::MAX;
+    let mut time = 0;
+
+    for t in 0..=100000 {
+        let (mut q1, mut q2, mut q3, mut q4) = (0, 0, 0, 0);
+        for (pos, vel) in robots.iter_mut() {
+            *pos = calc_pos(*pos, *vel, width, height, 1);
+            if pos.0 < width / 2 && pos.1 < height / 2 {
+                q1 += 1;
+            } else if pos.0 > width / 2 && pos.1 < height / 2 {
+                q2 += 1;
+            } else if pos.0 < width / 2 && pos.1 > height / 2 {
+                q3 += 1;
+            } else if pos.0 > width / 2 && pos.1 > height / 2 {
+                q4 += 1;
+            }
+        }
+
+        let e = q1 * q2 * q3 * q4;
+        if min_e > e {
+            time = t;
+            min_e = e;
+        }
+    }
+
+    time + 1
+}
+
+fn main() {
+    println!("Hello, this is Patrick!");
+
+    let input = include_str!("../input.txt");
+
+    let result_1 = solve_1(input, 101, 103);
+    println!("The safety factor will be {}", result_1);
+
+    let result_2 = solve_2(input, 101, 103);
+    println!("The time that the easter egg occurs is {}s", result_2);
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_1() {
+        let test_input = include_str!("../test.txt");
+        assert_eq!(solve_1(test_input, 11, 7), 12);
+    }
+
+    //#[test]
+    //fn test_2() {
+    //    //let test_input = include_str!("../test.txt");
+    //    //assert_eq!(solve_2(test_input), _);
+    //}
+}