refactor 81 and dijkstra

lib/dijkstra/src/lib.rs

@@ -6,6 +6,30 @@ type Coordinate = (usize, usize);
 
 const START: Coordinate = (0, 0);
 
+pub enum AllowedMovements {
+    DownRight,
+    DownRightUp,
+}
+
+impl AllowedMovements {
+    fn get_neighbours(&self, c: &Coordinate) -> Vec<Coordinate> {
+        match self {
+            Self::DownRight => self.get_neighbours_down_right(c),
+            Self::DownRightUp => self.get_neighbours_down_right_up(c),
+        }
+    }
+
+    fn get_neighbours_down_right(&self, (x0, y0): &Coordinate) -> Vec<Coordinate> {
+        vec![(*x0 + 1, *y0), (*x0, *y0 + 1)]
+    }
+
+    fn get_neighbours_down_right_up(&self, (x0, y0): &Coordinate) -> Vec<Coordinate> {
+        let mut result = self.get_neighbours_down_right(&(*x0, *y0));
+        result.push((*x0, *y0 - 1));
+        result
+    }
+}
+
 pub trait Matrix<T>
 where
     T: Add + PartialOrd + Debug + Copy,
@@ -26,6 +50,7 @@ pub struct Dijkstra<'a, T> {
     matrix: &'a mut dyn Matrix<T>,
     unvisited_with_distance: HashSet<Coordinate>,
     unvisited_without_distance: HashSet<Coordinate>,
+    allowed_movements: AllowedMovements,
 }
 
 impl<'a, T> Debug for Dijkstra<'a, T> {
@@ -40,13 +65,14 @@ impl<'a, T> Dijkstra<'a, T>
 where
     T: PartialOrd + Add<Output = T> + Display + Copy + Debug,
 {
-    pub fn new(matrix: &'a mut dyn Matrix<T>) -> Self {
+    pub fn new(matrix: &'a mut dyn Matrix<T>, allowed_movements: AllowedMovements) -> Self {
         let unvisited_with_distance = HashSet::new();
         let unvisited_without_distance = Self::initialize_unvisited_set(&*matrix, START);
         Self {
             matrix,
             unvisited_with_distance,
             unvisited_without_distance,
+            allowed_movements,
         }
     }
 
@@ -79,15 +105,19 @@ where
     }
 
     fn get_neighbours(&self, coordinate: &Coordinate) -> Vec<Coordinate> {
-        let (x0, y0) = coordinate;
-        let mut result = vec![];
-        if *x0 < self.matrix.width() - 1 {
-            result.push((*x0 + 1, *y0));
-        }
-        if *y0 < self.matrix.height() - 1 {
-            result.push((*x0, *y0 + 1));
-        }
-        result
+        let possible_neighbours = self.allowed_movements.get_neighbours(coordinate);
+        self.remove_out_of_bounds_neighbours(possible_neighbours)
+    }
+
+    fn remove_out_of_bounds_neighbours(&self, neighbours: Vec<Coordinate>) -> Vec<Coordinate> {
+        neighbours
+            .into_iter()
+            .filter(|c| self.is_in_bounds(c))
+            .collect()
+    }
+
+    fn is_in_bounds(&self, (x, y): &Coordinate) -> bool {
+        *x < self.matrix.width() && *y < self.matrix.height()
     }
 
     fn update_neighbour(&mut self, next: Coordinate, previous: Coordinate, previous_distance: T) {