day20 WIP

src/tasks/day20.rs

@@ -0,0 +1,129 @@
+use self::Tile::*;
+#[allow(unused_imports)]
+use crate::utils;
+use std::collections::HashMap;
+
+pub fn task1() {
+    // let input = utils::read_file("input/day20.txt");
+    let input = "^ENWWW(NEEE|SSE(EE|N))$".to_string();
+    let input = &input[1..];
+    let mut map: HashMap<Point, Tile> = HashMap::new();
+    add_default_neighbors_for_room(&mut map, Point(0, 0));
+    parse_input(&mut map, &input, Point(0, 0));
+
+    print_map(&map);
+}
+
+fn parse_input(map: &mut HashMap<Point, Tile>, input: &str, position: Point) {
+    let mut position = position;
+    let mut input = input;
+    while let Some(c) = input.chars().next() {
+        match c {
+            '(' => return,
+            'N' => {
+                position = Point(position.0, position.1 - 2);
+                add_default_neighbors_for_room(map, position);
+                map.insert(Point(position.0, position.1 + 1), Door);
+                input = &input[1..];
+            }
+            'E' => {
+                position = Point(position.0 + 2, position.1);
+                add_default_neighbors_for_room(map, position);
+                map.insert(Point(position.0 - 1, position.1), Door);
+                input = &input[1..];
+            }
+            'S' => {
+                position = Point(position.0, position.1 + 2);
+                add_default_neighbors_for_room(map, position);
+                map.insert(Point(position.0, position.1 - 1), Door);
+                input = &input[1..];
+            }
+            'W' => {
+                position = Point(position.0 - 2, position.1);
+                add_default_neighbors_for_room(map, position);
+                map.insert(Point(position.0 + 1, position.1), Door);
+                input = &input[1..];
+            }
+            '$' => return,
+            c => panic!(
+                "Stumbled upon a '{}' when reading input where it shouldn't be",
+                c
+            ),
+        }
+    }
+}
+
+fn add_default_neighbors_for_room(map: &mut HashMap<Point, Tile>, position: Point) {
+    map.insert(position, Room);
+    for p in position.diagonals() {
+        map.insert(p, Wall);
+    }
+    for p in position.neighbors() {
+        if !map.contains_key(&p) {
+            map.insert(p, Unknown);
+        }
+    }
+}
+
+fn print_map(map: &HashMap<Point, Tile>) {
+    let xmin = map.keys().min_by_key(|it| it.0).unwrap().0;
+    let xmax = map.keys().max_by_key(|it| it.0).unwrap().0;
+    let ymin = map.keys().min_by_key(|it| it.1).unwrap().1;
+    let ymax = map.keys().max_by_key(|it| it.1).unwrap().1;
+
+    for y in ymin..=ymax {
+        for x in xmin..=xmax {
+            if x == 0 && y == 0 {
+                print!("X")
+            } else {
+                print!(
+                    "{}",
+                    match map.get(&Point(x, y)) {
+                        None => " ",
+                        Some(Wall) => "#",
+                        Some(Room) => ".",
+                        Some(Unknown) => "?",
+                        Some(Door) => {
+                            if y % 2 == 0 {
+                                "|"
+                            } else {
+                                "-"
+                            }
+                        }
+                    }
+                );
+            }
+        }
+        println!();
+    }
+}
+
+#[derive(Eq, PartialEq, Hash, Clone, Copy, Debug)]
+struct Point(i32, i32);
+
+impl Point {
+    fn diagonals(&self) -> Vec<Point> {
+        vec![
+            Point(self.0 - 1, self.1 - 1),
+            Point(self.0 - 1, self.1 + 1),
+            Point(self.0 + 1, self.1 - 1),
+            Point(self.0 + 1, self.1 + 1),
+        ]
+    }
+
+    fn neighbors(&self) -> Vec<Point> {
+        vec![
+            Point(self.0 - 1, self.1),
+            Point(self.0 + 1, self.1),
+            Point(self.0, self.1 - 1),
+            Point(self.0, self.1 + 1),
+        ]
+    }
+}
+
+enum Tile {
+    Unknown,
+    Room,
+    Wall,
+    Door,
+}

src/tasks/mod.rs

@@ -13,3 +13,4 @@ pub mod day12;
 pub mod day13;
 pub mod day14;
 pub mod day15;
+pub mod day20;