Day 15 part 1

2022/rust/src/day15.rs

@@ -0,0 +1,122 @@
+mod common;
+
+type XY = (i64, i64);
+#[derive(Debug)]
+struct Sensor {
+    pos: XY,
+    nearest_beacon: XY,
+    taxi_dist_covered: u64,
+}
+
+type Input = Vec<Sensor>;
+type Answer = usize;
+
+fn taxi_dist(a: &XY, b: &XY) -> u64 {
+    a.0.abs_diff(b.0) + a.1.abs_diff(b.1) - 1
+}
+
+fn processed_input(input: &str) -> Input {
+    input
+        .lines()
+        .map(|s| {
+            let line_res = s
+                .split('=')
+                .skip(1)
+                .map(|s| {
+                    s.chars()
+                        .take_while(|c| *c == '-' || ('0'..='9').contains(c))
+                        .collect::<String>()
+                        .parse::<i64>()
+                        .unwrap()
+                })
+                .collect::<Vec<i64>>();
+
+            line_res
+        })
+        .map(|coords| {
+            let pos = (coords[0], coords[1]);
+            let nearest_beacon = (coords[2], coords[3]);
+            let taxi_dist_covered = taxi_dist(&pos, &nearest_beacon);
+            Sensor {
+                pos,
+                nearest_beacon,
+                taxi_dist_covered,
+            }
+        })
+        .collect()
+}
+
+fn part1(input: &Input, y: i64) -> Answer {
+    let (mut minx, mut maxx) = (i64::MAX, i64::MIN);
+    for s in input {
+        let (nminx, nmaxx) = (
+            s.pos.0 - (s.taxi_dist_covered as i64),
+            s.pos.0 + (s.taxi_dist_covered as i64),
+        );
+        if nminx < minx {
+            minx = nminx;
+        }
+        if nmaxx > maxx {
+            maxx = nmaxx;
+        }
+    }
+    let mut unbeaconable_locs = 0;
+    println!("{}..{}", minx, maxx);
+    for x in minx..=maxx {
+        for s in input {
+            if (x, y) == s.nearest_beacon {
+                break;
+            }
+            if taxi_dist(&s.pos, &(x, y)) <= s.taxi_dist_covered {
+                unbeaconable_locs += 1;
+                break;
+            }
+        }
+    }
+    println!("{:?}", input);
+    unbeaconable_locs
+}
+
+fn part2(input: &Input) -> Answer {
+    0
+}
+
+fn main() {
+    let input_text = common::day_input(15);
+    eprintln!("{}\n\nAbove is your input file.\n\n", input_text);
+    let input = processed_input(&input_text);
+    common::show_answers(&part1(&input, 2000000), &part2(&input))
+    // common::show_both_answers(&both_parts(&input))
+}
+
+// fn both_parts(input: &Input) -> (Answer, Answer) {
+//     (0, 0)
+// }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    const TEST_INPUT: &str = "Sensor at x=2, y=18: closest beacon is at x=-2, y=15
+Sensor at x=9, y=16: closest beacon is at x=10, y=16
+Sensor at x=13, y=2: closest beacon is at x=15, y=3
+Sensor at x=12, y=14: closest beacon is at x=10, y=16
+Sensor at x=10, y=20: closest beacon is at x=10, y=16
+Sensor at x=14, y=17: closest beacon is at x=10, y=16
+Sensor at x=8, y=7: closest beacon is at x=2, y=10
+Sensor at x=2, y=0: closest beacon is at x=2, y=10
+Sensor at x=0, y=11: closest beacon is at x=2, y=10
+Sensor at x=20, y=14: closest beacon is at x=25, y=17
+Sensor at x=17, y=20: closest beacon is at x=21, y=22
+Sensor at x=16, y=7: closest beacon is at x=15, y=3
+Sensor at x=14, y=3: closest beacon is at x=15, y=3
+Sensor at x=20, y=1: closest beacon is at x=15, y=3";
+
+    #[test]
+    fn test() {
+        let input = processed_input(TEST_INPUT);
+        assert_eq!(part1(&input, 10), 26);
+        assert_eq!(part2(&input), 0);
+        // assert_eq!(both_parts(&input), (0, 0));
+    }
+}