1 files changed, 157 insertions, 0 deletions
diff --git a/2020/src/bin/day_5.rs b/2020/src/bin/day_5.rs
new file mode 100644
index 0000000..15c8a70
--- /dev/null
+++ b/2020/src/bin/day_5.rs
@@ -0,0 +1,157 @@
+use bevy::prelude::*;
+use std::fs::File;
+use std::io::{BufRead, BufReader};
+
+fn main() {
+    App::build()
+        .add_resource(WindowDescriptor {
+            title: "Advent of Code".to_string(),
+            width: 1920,
+            height: 1080,
+            ..Default::default()
+        })
+        .add_resource(ClearColor(Color::rgb(0., 0., 0.)))
+        .add_startup_system(setup_camera.system())
+        .add_startup_system(read_input_file.system())
+        .add_startup_stage("search")
+        .add_startup_system_to_stage("search", find_unoccupied_seat.system())
+        .add_startup_stage("metadata")
+        .add_startup_system_to_stage("metadata", add_seat_ids.system())
+        .add_startup_system_to_stage("metadata", add_seat_sprites.system())
+        .add_startup_stage("report")
+        .add_startup_system_to_stage("report", print_highest_seat_id.system())
+        .add_startup_system_to_stage("report", print_my_seat_id.system())
+        .add_plugins(DefaultPlugins)
+        .run();
+}
+
+fn setup_camera(mut commands: Commands, mut materials: ResMut<Assets<ColorMaterial>>) {
+    commands.spawn(Camera2dComponents {
+        transform: Transform::from_translation(Vec3::new(80. / 2., 1280. / 2., 0.)),
+        ..Default::default()
+    });
+
+    commands.insert_resource(Materials {
+        my_seat_material: materials.add(Color::rgb(0., 0., 255.).into()),
+        seat_material: materials.add(Color::rgb(0., 255., 0.).into()),
+    });
+}
+
+struct Materials {
+    my_seat_material: Handle<ColorMaterial>,
+    seat_material: Handle<ColorMaterial>,
+}
+
+#[derive(PartialEq, Eq)]
+struct Position {
+    x: u32,
+    y: u32,
+}
+struct SeatId(u32);
+struct MySeat;
+
+fn read_input_file(mut commands: Commands) {
+    let f = File::open("./inputs/day_5.txt").unwrap();
+    for line in BufReader::new(f).lines() {
+        let mut max_y = 128;
+        let mut min_y = 0;
+        let mut max_x = 8;
+        let mut min_x = 0;
+        for c in line.unwrap().trim().chars() {
+            let mid_x = (min_x + max_x) / 2;
+            let mid_y = (min_y + max_y) / 2;
+            match c {
+                'F' => {
+                    max_y = mid_y;
+                }
+                'B' => {
+                    min_y = mid_y;
+                }
+                'L' => {
+                    max_x = mid_x;
+                }
+                'R' => {
+                    min_x = mid_x;
+                }
+                _ => panic!("Unexpected character {}", c),
+            }
+        }
+
+        assert_eq!(max_y - min_y, 1);
+        assert_eq!(max_x - min_x, 1);
+
+        commands.spawn((Position { x: min_x, y: min_y },));
+    }
+}
+
+fn find_unoccupied_seat(mut commands: Commands, seats: Query<&Position>) {
+    for y in 1..127 {
+        for x in 0..8 {
+            let potential_position = Position { x, y };
+            let required_left = if x == 0 {
+                Position { x: 7, y: y - 1 }
+            } else {
+                Position { x: x - 1, y }
+            };
+            let required_right = if x == 7 {
+                Position { x: 0, y: y + 1 }
+            } else {
+                Position { x: x + 1, y }
+            };
+
+            let required_surrounds = [required_left, required_right];
+            if !seats.iter().any(|p| p == &potential_position) {
+                if required_surrounds
+                    .iter()
+                    .all(|required| seats.iter().any(|p| p == required))
+                {
+                    commands.spawn((MySeat, potential_position));
+                }
+            }
+        }
+    }
+}
+
+fn add_seat_ids(mut commands: Commands, seats: Query<(Entity, &Position)>) {
+    for (entity, position) in seats.iter() {
+        let seat_id = position.y * 8 + position.x;
+        commands.insert_one(entity, SeatId(seat_id));
+    }
+}
+
+fn add_seat_sprites(
+    mut commands: Commands,
+    materials: Res<Materials>,
+    seats: Query<(Entity, &Position, Option<&MySeat>)>,
+) {
+    for (entity, position, my_seat) in seats.iter() {
+        commands.insert(
+            entity,
+            SpriteComponents {
+                sprite: Sprite::new(Vec2::new(10., 10.)),
+                material: if my_seat.is_some() {
+                    materials.my_seat_material.clone()
+                } else {
+                    materials.seat_material.clone()
+                },
+                transform: Transform::from_translation(Vec3::new(
+                    position.x as f32 * 10.,
+                    position.y as f32 * 10.,
+                    0.,
+                )),
+                ..Default::default()
+            },
+        );
+    }
+}
+
+fn print_highest_seat_id(seats: Query<&SeatId>) {
+    let max = seats.iter().map(|s| s.0).max();
+    println!("Max seat id: {:?}", max);
+}
+
+fn print_my_seat_id(seats: Query<With<MySeat, &SeatId>>) {
+    for seat_id in seats.iter() {
+        println!("My seat id: {}", seat_id.0);
+    }
+}