wip

example/day15.txt

@@ -0,0 +1,14 @@
+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

input/day15.txt

@@ -0,0 +1,38 @@
+Sensor at x=2793338, y=1910659: closest beacon is at x=2504930, y=2301197
+Sensor at x=2887961, y=129550: closest beacon is at x=2745008, y=-872454
+Sensor at x=3887055, y=2785942: closest beacon is at x=4322327, y=2605441
+Sensor at x=3957399, y=2164042: closest beacon is at x=3651713, y=1889668
+Sensor at x=1268095, y=1265989: closest beacon is at x=1144814, y=2000000
+Sensor at x=2093967, y=2103436: closest beacon is at x=2504930, y=2301197
+Sensor at x=2980126, y=1348046: closest beacon is at x=3651713, y=1889668
+Sensor at x=508134, y=3998686: closest beacon is at x=1123963, y=4608563
+Sensor at x=2982740, y=3604350: closest beacon is at x=2756683, y=3240616
+Sensor at x=2372671, y=3929034: closest beacon is at x=2756683, y=3240616
+Sensor at x=437628, y=1124644: closest beacon is at x=570063, y=959065
+Sensor at x=3271179, y=3268845: closest beacon is at x=3444757, y=3373782
+Sensor at x=1899932, y=730465: closest beacon is at x=570063, y=959065
+Sensor at x=1390358, y=3881569: closest beacon is at x=1123963, y=4608563
+Sensor at x=554365, y=989190: closest beacon is at x=570063, y=959065
+Sensor at x=2225893, y=2703661: closest beacon is at x=2504930, y=2301197
+Sensor at x=3755905, y=1346206: closest beacon is at x=3651713, y=1889668
+Sensor at x=3967103, y=3930797: closest beacon is at x=3444757, y=3373782
+Sensor at x=3534099, y=2371166: closest beacon is at x=3651713, y=1889668
+Sensor at x=3420789, y=1720583: closest beacon is at x=3651713, y=1889668
+Sensor at x=2222479, y=3278186: closest beacon is at x=2756683, y=3240616
+Sensor at x=100457, y=871319: closest beacon is at x=570063, y=959065
+Sensor at x=1330699, y=2091946: closest beacon is at x=1144814, y=2000000
+Sensor at x=598586, y=99571: closest beacon is at x=570063, y=959065
+Sensor at x=3436099, y=3392932: closest beacon is at x=3444757, y=3373782
+Sensor at x=3338431, y=3346334: closest beacon is at x=3444757, y=3373782
+Sensor at x=3892283, y=688090: closest beacon is at x=3651713, y=1889668
+Sensor at x=1485577, y=1929020: closest beacon is at x=1144814, y=2000000
+Sensor at x=2991003, y=2951060: closest beacon is at x=2756683, y=3240616
+Sensor at x=2855486, y=2533468: closest beacon is at x=2504930, y=2301197
+Sensor at x=750865, y=1619637: closest beacon is at x=1144814, y=2000000
+Sensor at x=3378101, y=3402212: closest beacon is at x=3444757, y=3373782
+Sensor at x=3515528, y=2950404: closest beacon is at x=3444757, y=3373782
+Sensor at x=163133, y=2640553: closest beacon is at x=-1016402, y=3057364
+Sensor at x=1765550, y=3021994: closest beacon is at x=2756683, y=3240616
+Sensor at x=534625, y=1056421: closest beacon is at x=570063, y=959065
+Sensor at x=3418549, y=3380980: closest beacon is at x=3444757, y=3373782
+Sensor at x=29, y=389033: closest beacon is at x=570063, y=959065

src/day15.rs

@@ -0,0 +1,132 @@
+//! Day 15: Beacon Exclusion Zone
+
+use std::collections::HashSet;
+
+use once_cell::sync::Lazy;
+use regex::Regex;
+
+type Coord = (i32, i32);
+
+fn parse_input(input: &[String]) -> Vec<(Coord, Coord)> {
+    static LINE_REGEX: Lazy<Regex> = Lazy::new(|| {
+        Regex::new("Sensor at x=(-?\\d+), y=(-?\\d+): closest beacon is at x=(-?\\d+), y=(-?\\d+)")
+            .unwrap()
+    });
+
+    input
+        .iter()
+        .map(|line| {
+            let cap = LINE_REGEX.captures(line).unwrap();
+            (
+                (
+                    cap.get(1).unwrap().as_str().parse().unwrap(),
+                    cap.get(2).unwrap().as_str().parse().unwrap(),
+                ),
+                (
+                    cap.get(3).unwrap().as_str().parse().unwrap(),
+                    cap.get(4).unwrap().as_str().parse().unwrap(),
+                ),
+            )
+        })
+        .collect()
+}
+
+fn mdist(p1: Coord, p2: Coord) -> i32 {
+    (p1.0.abs_diff(p2.0) + p1.1.abs_diff(p2.1)) as i32
+}
+
+fn beacon_exclude(pos: Coord, closest: Coord, excluded: &mut HashSet<Coord>, row: i32) {
+    let dist = mdist(pos, closest);
+
+    for x in pos.0 - dist..pos.0 + dist {
+        let point = (x, row);
+        if point != closest && mdist(pos, point) <= dist {
+            excluded.insert(point);
+        }
+    }
+}
+
+fn beacon_exclude_section(pos: Coord, closest: Coord, excluded: &mut HashSet<Coord>, limit: i32) {
+    let dist = mdist(pos, closest);
+
+    for y in 0..=limit {
+        for x in 0..=limit {
+            let point = (x, y);
+            if mdist(pos, point) <= dist {
+                excluded.insert(point);
+            }
+        }
+    }
+}
+
+fn _part1(input: Vec<String>, row: i32) -> String {
+    let sensors = parse_input(&input);
+    let mut excluded = HashSet::new();
+
+    sensors
+        .iter()
+        .for_each(|(pos, closest)| beacon_exclude(*pos, *closest, &mut excluded, row));
+
+    excluded.len().to_string()
+}
+
+fn _part2(input: Vec<String>, limit: i32) -> String {
+    let sensors = parse_input(&input);
+    let mut excluded = HashSet::new();
+
+    sensors
+        .iter()
+        .enumerate()
+        .for_each(|(i, (pos, closest))| {
+            println!("bc {}", i);
+            beacon_exclude_section(*pos, *closest, &mut excluded, limit);
+        });
+
+    for y in 0..limit {
+        for x in 0..limit {
+            let point = (x, y);
+            if !excluded.contains(&point) {
+                dbg!(&point);
+                let f = point.0 * 4000000 + point.1;
+                return f.to_string();
+            }
+        }
+    }
+
+    panic!("not found")
+}
+
+pub fn part1(input: Vec<String>) -> String {
+    _part1(input, 2000000)
+}
+
+pub fn part2(input: Vec<String>) -> String {
+    _part2(input, 4000000)
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    const DAY: u8 = 15;
+
+    #[test]
+    fn t_example1() {
+        assert_eq!(_part1(crate::read_example(DAY), 10), "26");
+    }
+
+    #[test]
+    fn t_example2() {
+        assert_eq!(_part2(crate::read_example(DAY), 20), "56000011");
+    }
+
+    #[test]
+    fn t_part1() {
+        assert_eq!(part1(crate::read_input(DAY)), "");
+    }
+
+    #[test]
+    fn t_part2() {
+        assert_eq!(part2(crate::read_input(DAY)), "");
+    }
+}

src/main.rs

@@ -22,6 +22,7 @@ mod day11;
 mod day12;
 mod day13;
 mod day14;
+mod day15;
 
 pub(crate) fn read_input(day: u8) -> Vec<String> {
     read_input_file(path!("input" / format!("day{}.txt", day)))
@@ -77,6 +78,7 @@ days! {
     12, day12,
     13, day13,
     14, day14,
+    15, day15,
 }
 
 fn main() {