day(22): switch to proper vectors

Signed-off-by: Matej Focko <me@mfocko.xyz>

src/bin/day22.rs

@@ -5,6 +5,10 @@ use aoc_2022::*;
 type Input = MonkeyMap;
 type Output = isize;
 
+type Position = Vector2D<usize>;
+type Direction = Vector2D<isize>;
+type Boundary = Vector2D<usize>;
+
 enum Instruction {
     Move(usize),
     TurnLeft,
@@ -19,56 +23,90 @@ enum Orientation {
 
 struct MonkeyMap {
     map: Vec<Vec<char>>,
-    boundaries: HashMap<Orientation, (usize, usize)>,
+    boundaries: HashMap<Orientation, Boundary>,
     instructions: Vec<Instruction>,
 }
 
+fn wrapping_step(position: usize, diff: isize, range: Boundary) -> usize {
+    let (lower, upper) = (range.x(), range.y());
+    let range_size = (upper - lower) as isize;
+
+    (lower as isize + (position as isize + diff - lower as isize + range_size) % range_size)
+        as usize
+}
+
 trait Wrap {
-    fn next(&self, state: &State<'_>) -> (usize, usize);
+    fn next(&self, state: &State<'_>) -> (Position, Direction);
 }
 
 struct Wrap2D;
-impl Wrap2D {
-    fn step(position: usize, diff: isize, lower: usize, upper: usize) -> usize {
-        let range_size = (upper - lower) as isize;
-        (lower as isize + (position as isize + diff - lower as isize + range_size) % range_size)
-            as usize
-    }
-}
 impl Wrap for Wrap2D {
-    fn next(&self, state: &State<'_>) -> (usize, usize) {
-        let h_bound = state.input.boundaries[&Orientation::Horizontal(state.y)];
-        let v_bound = state.input.boundaries[&Orientation::Vertical(state.x)];
-
-        let (dx, dy) = state.direction;
+    fn next(&self, state: &State<'_>) -> (Position, Direction) {
+        let h_bound = state.input.boundaries[&Orientation::Horizontal(state.position.y())];
+        let v_bound = state.input.boundaries[&Orientation::Vertical(state.position.x())];
 
         (
-            Self::step(state.x, dx, h_bound.0, h_bound.1),
-            Self::step(state.y, dy, v_bound.0, v_bound.1),
+            Position::new(
+                wrapping_step(state.position.x(), state.direction.x(), h_bound),
+                wrapping_step(state.position.y(), state.direction.y(), v_bound),
+            ),
+            state.direction,
+        )
+    }
+}
+
+struct Face {
+    horizontal_bound: Boundary,
+    vertical_bound: Boundary,
+}
+
+struct Wrap3D {
+    faces: Vec<Face>,
+}
+impl Wrap3D {
+    fn face(&self, position: Position) -> &Face {
+        let (x, y) = (position.x(), position.y());
+
+        for f in &self.faces {}
+        todo!()
+    }
+}
+impl Wrap for Wrap3D {
+    fn next(&self, state: &State<'_>) -> (Position, Direction) {
+        let face = self.face(state.position);
+
+        (
+            Position::new(
+                wrapping_step(
+                    state.position.x(),
+                    state.direction.x(),
+                    face.horizontal_bound,
+                ),
+                wrapping_step(state.position.y(), state.direction.y(), face.vertical_bound),
+            ),
+            state.direction,
         )
     }
 }
 
 struct State<'a> {
     input: &'a Input,
-    y: usize,
-    x: usize,
-    direction: (isize, isize),
+    position: Position,
+    direction: Direction,
 }
 
 impl<'a> State<'a> {
     fn new(input: &'a Input) -> State<'a> {
         Self {
             input,
-            y: 0,
-            x: input.boundaries[&Orientation::Horizontal(0)].0,
-            direction: (1, 0),
+            position: Position::new(input.boundaries[&Orientation::Horizontal(0)].x(), 0),
+            direction: Direction::new(1, 0),
         }
     }
 
     fn is_blocked(&self, wrapper: &impl Wrap) -> bool {
-        let (x, y) = wrapper.next(self);
-        self.input.map[y][x] == '#'
+        let (next_position, _) = wrapper.next(self);
+        self.input.map[next_position] == '#'
     }
 
     fn step(&mut self, wrapper: &impl Wrap, steps: usize) {
@@ -76,18 +114,18 @@ impl<'a> State<'a> {
             if self.is_blocked(wrapper) {
                 return;
             }
-            (self.x, self.y) = wrapper.next(self);
+            (self.position, self.direction) = wrapper.next(self);
         }
     }
 
     fn turn_left(&mut self) {
-        let (x, y) = self.direction;
-        self.direction = (y, -x);
+        let previous = self.direction;
+        self.direction = Direction::new(previous.y(), -previous.x());
     }
 
     fn turn_right(&mut self) {
-        let (x, y) = self.direction;
-        self.direction = (-y, x);
+        let previous = self.direction;
+        self.direction = Direction::new(-previous.y(), previous.x());
     }
 }
 
@@ -110,7 +148,9 @@ fn solve(wrapper: &impl Wrap, input: &Input) -> Output {
             state
         });
 
-    (1000 * (final_state.y + 1) + 4 * (final_state.x + 1) + DIRECTIONS[&final_state.direction])
+    (1000 * (final_state.position.y() + 1)
+        + 4 * (final_state.position.x() + 1)
+        + DIRECTIONS[&(final_state.direction.x(), final_state.direction.y())])
         .try_into()
         .unwrap()
 }
@@ -133,7 +173,7 @@ impl Solution<Input, Output> for Day22 {
             let mut last_non_empty = first_non_empty.skip_while(|&(_, &c)| c != ' ');
             let end = last_non_empty.next().unwrap_or((map[row].len(), &'_')).0;
 
-            boundaries.insert(Orientation::Horizontal(row), (start, end));
+            boundaries.insert(Orientation::Horizontal(row), Boundary::new(start, end));
         }
 
         for col in 0..map[0].len() {
@@ -145,7 +185,7 @@ impl Solution<Input, Output> for Day22 {
             let mut last_non_empty = first_non_empty.skip_while(|&(_, &c)| c != ' ');
             let end = last_non_empty.next().unwrap_or((map.len(), &'_')).0;
 
-            boundaries.insert(Orientation::Vertical(col), (start, end));
+            boundaries.insert(Orientation::Vertical(col), Boundary::new(start, end));
         }
 
         let unparsed_instructions_str = instructions.trim_end();
@@ -185,8 +225,9 @@ impl Solution<Input, Output> for Day22 {
         solve(&Wrap2D, input)
     }
 
-    fn part_2(_input: &Input) -> Output {
-        todo!()
+    fn part_2(input: &Input) -> Output {
+        let wrapper = Wrap2D;
+        solve(&wrapper, input)
     }
 }