feat: added part 1 of day 10

ankjevel · ankjevel · commit 548ee58262de · 2020-12-05T12:06:17.000+01:00
diff --git a/README.md b/README.md
@@ -12,3 +12,4 @@
 - [Day 7](https://github.com/ankjevel/adventofcode/tree/2019/day_07) 🌟 🌟
 - [Day 8](https://github.com/ankjevel/adventofcode/tree/2019/day_08) 🌟 🌟
 - [Day 9](https://github.com/ankjevel/adventofcode/tree/2019/day_09) 🌟 🌟
+- [Day 10](https://github.com/ankjevel/adventofcode/tree/2019/day_10) 🌟
diff --git a/day_10/Cargo.toml b/day_10/Cargo.toml
@@ -0,0 +1,14 @@
+[package]
+name = "day_10"
+version = "0.1.0"
+authors = ["Dennis Pettersson <mail@dennispettersson.se>"]
+edition = "2018"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+float-cmp = "0.6.0"
+
+[[bin]]
+name = "day_10"
+path = "src/bin/main.rs"
diff --git a/day_10/src/bin/main.rs b/day_10/src/bin/main.rs
@@ -0,0 +1,102 @@
+use ::day_10::{parse_input, part_01::main as part_01, to_points};
+
+fn main() {
+    let input = to_points(&parse_input(include_str!("../../../input/day_10")));
+    println!("part_01: {}", part_01(&input).0);
+}
+
+#[cfg(test)]
+#[allow(dead_code)]
+mod tests {
+    use ::day_10::{parse_input, part_01::main as part_01, point::Point, to_points};
+
+    const EXAMPLE_01_00: &'static str = "
+        .#..#
+        .....
+        #####
+        ....#
+        ...x#
+    ";
+
+    const EXAMPLE_01_01: &'static str = "
+        ......#.#.
+        #..#.#....
+        ..#######.
+        .#.#.###..
+        .#..#.....
+        ..#....#.#
+        #..#....#.
+        .##.#..###
+        ##...x..#.
+        .#....####
+    ";
+
+    const EXAMPLE_01_02: &'static str = "
+        #.#...#.#.
+        .###....#.
+        .x....#...
+        ##.#.#.#.#
+        ....#.#.#.
+        .##..###.#
+        ..#...##..
+        ..##....##
+        ......#...
+        .####.###.
+    ";
+
+    const EXAMPLE_01_03: &'static str = "
+        .#..#..###
+        ####.###.#
+        ....###.#.
+        ..###.x#.#
+        ##.##.#.#.
+        ....###..#
+        ..#.#..#.#
+        #..#.#.###
+        .##...##.#
+        .....#.#..
+    ";
+
+    const EXAMPLE_01_04: &'static str = "
+        .#..##.###...#######
+        ##.############..##.
+        .#.######.########.#
+        .###.#######.####.#.
+        #####.##.#.##.###.##
+        ..#####..#.#########
+        ####################
+        #.####....###.#.#.##
+        ##.#################
+        #####.##.###..####..
+        ..######..##.#######
+        ####.##.####...##..#
+        .#####..#.######.###
+        ##...#.####x#####...
+        #.##########.#######
+        .####.#.###.###.#.##
+        ....##.##.###..#####
+        .#.#.###########.###
+        #.#.#.#####.####.###
+        ###.##.####.##.#..##
+    ";
+
+    #[test]
+    fn it_gets_the_examples_on_part_01_right() {
+        let inputs: Vec<Vec<Point>> = vec![
+            EXAMPLE_01_00,
+            EXAMPLE_01_01,
+            EXAMPLE_01_02,
+            EXAMPLE_01_03,
+            EXAMPLE_01_04,
+        ]
+        .into_iter()
+        .map(|example| to_points(&parse_input(&example)))
+        .collect();
+
+        assert_eq!(part_01(&inputs[0]), (8, Some(Point { x: 3, y: 4 })));
+        assert_eq!(part_01(&inputs[1]), (33, Some(Point { x: 5, y: 8 })));
+        assert_eq!(part_01(&inputs[2]), (35, Some(Point { x: 1, y: 2 })));
+        assert_eq!(part_01(&inputs[3]), (41, Some(Point { x: 6, y: 3 })));
+        assert_eq!(part_01(&inputs[4]), (210, Some(Point { x: 11, y: 13 })));
+    }
+}
diff --git a/day_10/src/lib.rs b/day_10/src/lib.rs
@@ -0,0 +1,31 @@
+#[macro_use]
+extern crate float_cmp;
+
+pub mod part_01;
+pub mod point;
+
+pub type Input = Vec<Vec<char>>;
+
+pub fn to_points(input: &Input) -> Vec<point::Point> {
+    let mut points = Vec::new();
+    for (y, row) in input.into_iter().enumerate() {
+        for (x, item) in row.into_iter().enumerate() {
+            if item == &'.' {
+                continue;
+            }
+
+            points.push(point::Point::from_usize(x, y));
+        }
+    }
+
+    points
+}
+
+pub fn parse_input(string: &str) -> Input {
+    string
+        .lines()
+        .map(|string| string.trim())
+        .filter(|string| !string.is_empty())
+        .map(|string| string.chars().collect())
+        .collect()
+}
diff --git a/day_10/src/part_01.rs b/day_10/src/part_01.rs
@@ -0,0 +1,55 @@
+use crate::point::Point;
+
+fn distance(p1: &Point, p2: &Point) -> f64 {
+    ((p2.x as f64 - p1.x as f64).powf(2f64) + (p2.y as f64 - p1.y as f64).powf(2f64)).sqrt()
+}
+
+fn is_between(a: &Point, c: &Point, b: &Point) -> bool {
+    approx_eq!(
+        f64,
+        distance(&a, &c) + distance(&c, &b),
+        distance(&a, &b),
+        ulps = 2
+    )
+}
+
+pub fn main(input: &Vec<Point>) -> (u32, Option<Point>) {
+    let mut max = 0;
+    let mut best_match = None;
+
+    'a: for a in input {
+        let mut new_max = 0;
+        let mut matches = Vec::new();
+
+        'b: for b in input {
+            if b == a {
+                continue 'b;
+            }
+
+            let mut intersected = false;
+
+            'c: for c in input {
+                if a == c || b == c {
+                    continue 'c;
+                }
+
+                if is_between(a, c, b) {
+                    intersected = true;
+                    break 'c;
+                }
+            }
+
+            if !intersected {
+                matches.push(b.clone());
+                new_max += 1;
+            }
+        }
+
+        if new_max > max {
+            best_match = Some(a.clone());
+            max = new_max;
+        }
+    }
+
+    (max, best_match)
+}
diff --git a/day_10/src/point.rs b/day_10/src/point.rs
@@ -0,0 +1,14 @@
+#[derive(Clone, Copy, Eq, PartialEq, Hash, Debug)]
+pub struct Point {
+    pub x: u64,
+    pub y: u64,
+}
+
+impl Point {
+    pub fn from_usize(x: usize, y: usize) -> Point {
+        Point {
+            x: x as u64,
+            y: y as u64,
+        }
+    }
+}
