[TASK] Day 15 pt 1

Cargo.lock

@@ -8,6 +8,7 @@ version = "0.1.0"
 dependencies = [
  "lazy_static",
  "nohash-hasher",
+ "num",
  "regex",
  "rustc-hash",
 ]
@@ -21,6 +22,12 @@ dependencies = [
  "memchr",
 ]
 
+[[package]]
+name = "autocfg"
+version = "1.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d468802bab17cbc0cc575e9b053f41e72aa36bfa6b7f55e3529ffa43161b97fa"
+
 [[package]]
 name = "lazy_static"
 version = "1.4.0"
@@ -39,6 +46,82 @@ version = "0.2.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "2bf50223579dc7cdcfb3bfcacf7069ff68243f8c363f62ffa99cf000a6b9c451"
 
+[[package]]
+name = "num"
+version = "0.4.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "43db66d1170d347f9a065114077f7dccb00c1b9478c89384490a3425279a4606"
+dependencies = [
+ "num-bigint",
+ "num-complex",
+ "num-integer",
+ "num-iter",
+ "num-rational",
+ "num-traits",
+]
+
+[[package]]
+name = "num-bigint"
+version = "0.4.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f93ab6289c7b344a8a9f60f88d80aa20032336fe78da341afc91c8a2341fc75f"
+dependencies = [
+ "autocfg",
+ "num-integer",
+ "num-traits",
+]
+
+[[package]]
+name = "num-complex"
+version = "0.4.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7ae39348c8bc5fbd7f40c727a9925f03517afd2ab27d46702108b6a7e5414c19"
+dependencies = [
+ "num-traits",
+]
+
+[[package]]
+name = "num-integer"
+version = "0.1.45"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "225d3389fb3509a24c93f5c29eb6bde2586b98d9f016636dff58d7c6f7569cd9"
+dependencies = [
+ "autocfg",
+ "num-traits",
+]
+
+[[package]]
+name = "num-iter"
+version = "0.1.43"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7d03e6c028c5dc5cac6e2dec0efda81fc887605bb3d884578bb6d6bf7514e252"
+dependencies = [
+ "autocfg",
+ "num-integer",
+ "num-traits",
+]
+
+[[package]]
+name = "num-rational"
+version = "0.4.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0638a1c9d0a3c0914158145bc76cff373a75a627e6ecbfb71cbe6f453a5a19b0"
+dependencies = [
+ "autocfg",
+ "num-bigint",
+ "num-integer",
+ "num-traits",
+]
+
+[[package]]
+name = "num-traits"
+version = "0.2.15"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "578ede34cf02f8924ab9447f50c28075b4d3e5b269972345e7e0372b38c6cdcd"
+dependencies = [
+ "autocfg",
+]
+
 [[package]]
 name = "regex"
 version = "1.7.0"

Cargo.toml

@@ -10,4 +10,5 @@ edition = "2021"
 regex = "1"
 lazy_static = "1.4.0"
 rustc-hash = "1.1.0"
-nohash-hasher = "0.2.0"
+nohash-hasher = "0.2.0"
+num = "0.4.0"

input/day15.txt

@@ -0,0 +1,31 @@
+Sensor at x=3923513, y=2770279: closest beacon is at x=3866712, y=2438950
+Sensor at x=675683, y=3223762: closest beacon is at x=-224297, y=2997209
+Sensor at x=129453, y=2652332: closest beacon is at x=92656, y=2629486
+Sensor at x=3906125, y=2154618: closest beacon is at x=3866712, y=2438950
+Sensor at x=65723, y=902062: closest beacon is at x=92656, y=2629486
+Sensor at x=3137156, y=2876347: closest beacon is at x=2907507, y=3100765
+Sensor at x=32848, y=2676435: closest beacon is at x=92656, y=2629486
+Sensor at x=3272472, y=3445147: closest beacon is at x=2907507, y=3100765
+Sensor at x=2926008, y=128948: closest beacon is at x=3089364, y=-501737
+Sensor at x=2975, y=2769838: closest beacon is at x=92656, y=2629486
+Sensor at x=3540455, y=2469135: closest beacon is at x=3866712, y=2438950
+Sensor at x=3674809, y=2062166: closest beacon is at x=3719980, y=2000000
+Sensor at x=3693706, y=2027384: closest beacon is at x=3719980, y=2000000
+Sensor at x=3869683, y=2291983: closest beacon is at x=3866712, y=2438950
+Sensor at x=2666499, y=2796436: closest beacon is at x=2650643, y=2489479
+Sensor at x=492, y=2601991: closest beacon is at x=92656, y=2629486
+Sensor at x=2710282, y=3892347: closest beacon is at x=2907507, y=3100765
+Sensor at x=28974, y=3971342: closest beacon is at x=-224297, y=2997209
+Sensor at x=3990214, y=2399722: closest beacon is at x=3866712, y=2438950
+Sensor at x=3853352, y=1009020: closest beacon is at x=3719980, y=2000000
+Sensor at x=1231833, y=3999338: closest beacon is at x=1313797, y=4674300
+Sensor at x=2083669, y=875035: closest beacon is at x=1369276, y=-160751
+Sensor at x=1317274, y=2146819: closest beacon is at x=2650643, y=2489479
+Sensor at x=3712875, y=2018770: closest beacon is at x=3719980, y=2000000
+Sensor at x=963055, y=23644: closest beacon is at x=1369276, y=-160751
+Sensor at x=3671967, y=64054: closest beacon is at x=3089364, y=-501737
+Sensor at x=3109065, y=2222392: closest beacon is at x=2650643, y=2489479
+Sensor at x=3218890, y=1517419: closest beacon is at x=3719980, y=2000000
+Sensor at x=3856777, y=3987650: closest beacon is at x=4166706, y=3171774
+Sensor at x=1912696, y=3392788: closest beacon is at x=2907507, y=3100765
+Sensor at x=3597620, y=3100104: closest beacon is at x=4166706, y=3171774

input/day15_example.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

src/day15.rs

@@ -0,0 +1,126 @@
+use std::collections::HashSet;
+
+use regex::Regex;
+
+use crate::{day_solver::DaySolver, util::Coord};
+
+use super::util;
+
+pub struct Day15 {
+    beacon_scanners: Vec<BeaconScanner>
+}
+
+impl Day15 {
+
+    pub fn create() -> Self {
+        // let lines = util::read_file("input/day15_example.txt");
+        let lines = util::read_file("input/day15.txt");
+
+        // Lines look like:
+        // "Sensor at x=2, y=18: closest beacon is at x=-2, y=15"
+        let re = Regex::new(r"Sensor at x=(-?\d+), y=(-?\d+): closest beacon is at x=(-?\d+), y=(-?\d+)").unwrap();
+        // Put the input into the day struct
+        return Day15 {
+            beacon_scanners: lines.iter().map(|s| {
+                let cap = re.captures_iter(s).next().unwrap();
+                BeaconScanner {
+                    sensor: Coord { x: cap[1].parse::<i32>().unwrap(), y: cap[2].parse::<i32>().unwrap() },
+                    closest_beacon: Coord { x: cap[3].parse::<i32>().unwrap(), y: cap[4].parse::<i32>().unwrap() }
+                }
+            }).collect()
+        }
+    }
+
+}
+
+impl DaySolver for Day15 {
+
+
+    fn solve_part1(&mut self) -> String {
+
+        // print!("{:?}", self.beacon_scanners);
+
+        let check_y = if self.beacon_scanners.len() < 20  { 10 } else { 2_000_000 };
+
+        let mut ranges_covered: Vec<Range> = self.beacon_scanners.iter().filter_map(|bs| {
+            let sensor_dist = bs.sensor.manhattan_dist(&bs.closest_beacon);
+            let dist_to_check_y = bs.sensor.y.abs_diff(check_y) as i32;
+            let coverage_width = sensor_dist - dist_to_check_y;
+            // println!("Sensor at {},{} sees beacon {},{} at distance {}, and distance {} to check_y. So it covers {} cells", 
+            //     bs.sensor.x, bs.sensor.y, bs.closest_beacon.x, bs.closest_beacon.y, sensor_dist, dist_to_check_y, coverage_width);
+            if coverage_width < 0 {
+                None
+            } else {
+                // println!("Adding");
+                Some(Range{ 
+                    min: bs.sensor.x - coverage_width,
+                    max: bs.sensor.x + coverage_width 
+                })
+            }
+        }).collect();
+
+        if ranges_covered.is_empty() {
+            return 0.to_string();
+        }
+
+        // println!("Ranges covered: {:?}", ranges_covered);
+
+        // Now we need to merge all overlapping rangen into one, so we don't count any double ones:
+        // Note: there can be no beacons inside the sensor ranges, because if there were, the sensor 
+        // would pick up that one and have a smaller range 
+        ranges_covered.sort_by_key(|r| r.min);
+
+        // println!("Ranges covered: {:?}", ranges_covered);
+
+        let mut merged_ranges: Vec<Range> = Vec::new();
+        let mut ranges_covered_iter = ranges_covered.iter();
+        let mut current_range = ranges_covered_iter.next().unwrap().clone();
+        while let Some(next_range) = ranges_covered_iter.next() {
+            if current_range.overlaps(next_range) {
+                current_range.max = next_range.max.max(current_range.max);
+            } else {
+                // New range!
+                merged_ranges.push(current_range);
+                current_range = next_range.clone();
+            }
+        }
+        merged_ranges.push(current_range);
+
+        let beacons_on_check_y = self.beacon_scanners.iter()
+            .filter(|bs| bs.closest_beacon.y == check_y)
+            .map(|bs| bs.closest_beacon.x)
+            .filter(|x| merged_ranges.iter().any(|r| r.in_range(&x)))
+            .collect::<HashSet<i32>>();
+
+        // println!("Merged ranges: {:?}", merged_ranges);
+
+        return (merged_ranges.iter().map(|r| r.max - r.min + 1).sum::<i32>() - beacons_on_check_y.len() as i32).to_string();
+    
+    }
+
+    fn solve_part2(&mut self) -> String {
+        return 0.to_string();
+    }
+}
+
+#[derive(Debug, Clone)]
+struct BeaconScanner {
+    sensor: Coord<i32>,
+    closest_beacon: Coord<i32>
+}
+
+#[derive(Debug, Clone)]
+struct Range {
+    min: i32,
+    max: i32
+}
+
+impl Range {
+    pub fn overlaps(&self, other: &Range) -> bool {
+        self.min <= other.max && self.max >= other.min
+    }
+
+    pub fn in_range(&self, x: &i32) -> bool {
+        self.min.le(&x) && self.max.ge(&x)
+    }
+}

src/main.rs

@@ -13,6 +13,7 @@ use crate::day11::Day11;
 use crate::day12::Day12;
 use crate::day13::Day13;
 use crate::day14::Day14;
+use crate::day15::Day15;
 use crate::day_solver::DaySolver;
 
 mod util;
@@ -31,8 +32,9 @@ mod day11;
 mod day12;
 mod day13;
 mod day14;
+mod day15;
 
-const MAX_DAY: u8 = 14;
+const MAX_DAY: u8 = 15;
 const DEFAULT_BENCHMARK_AMOUNT: u32 = 100;
 
 fn main() {
@@ -110,6 +112,7 @@ fn build_day_solver(day: u8) -> Option<Box<dyn DaySolver>> {
         12 => Some(Box::new(Day12::create())),
         13 => Some(Box::new(Day13::create())),
         14 => Some(Box::new(Day14::create())),
+        15 => Some(Box::new(Day15::create())),
         _ => None
     }
 }

src/util.rs

@@ -1,6 +1,8 @@
 use std::fmt::Display;
 use std::fs;
 
+use num::Integer;
+
 pub fn read_file(filename: &str) -> Vec<String> {
 
     let contents = fs::read_to_string(filename)
@@ -82,3 +84,9 @@ pub struct Coord<T> where T: Sized {
     pub y: T
 }
 
+impl <T> Coord<T> where T: Integer + Copy {
+    pub fn manhattan_dist(&self, other: &Coord<T>) -> T {
+        self.x.max(other.x).sub(self.x.min(other.x)) + self.y.max(other.y).sub(self.y.min(other.y))
+    }
+}
+