✨

Author: Platane

packages/solver-r/src/grid.rs

@@ -181,6 +181,12 @@ impl<T: Copy> Grid<T> {
     }
 }
 
+impl Grid<Color> {
+    pub fn is_walkable(&self, walkable: Color, p: &Point) -> bool {
+        !self.is_inside(p) || self.get(p) <= walkable
+    }
+}
+
 #[test]
 fn it_should_sort_cell() {
     assert_eq!(Color::Empty < Color::Color1, true);

packages/solver-r/src/pocket.rs

@@ -0,0 +1,213 @@
+use crate::grid::{add, Color, Grid, Point, DIRECTIONS};
+use std::collections::{HashMap, HashSet};
+
+pub fn get_pocket_size(color_grid: &Grid<Color>, walkable: Color, p: &Point) -> usize {
+    let mut filled: HashSet<Point> = HashSet::new();
+    let mut open_list: Vec<Point> = Vec::new();
+    open_list.push(*p);
+
+    while let Some(p) = open_list.pop() {
+        if filled.contains(&p) {
+            continue;
+        }
+        if !color_grid.is_inside(&p) {
+            return usize::MAX;
+        }
+        if !(color_grid.get(&p) <= walkable) {
+            continue;
+        }
+
+        let reachable: bool = 'outer: {
+            let mut open_list: Vec<Point> = Vec::new();
+            let mut close_list: HashSet<Point> = HashSet::new();
+            let mut color: HashMap<Point, i8> = HashMap::new();
+
+            for (i, dir) in DIRECTIONS.iter().enumerate() {
+                let q = add(&p, &dir);
+                if color_grid.is_walkable(walkable, &q) {
+                    color.insert(q, i as i8);
+                    open_list.push(q);
+                }
+            }
+
+            while let Some(u) = open_list.pop() {
+                if close_list.contains(&u) {
+                    continue;
+                }
+
+                let i = *color.get(&u).unwrap();
+
+                for dir in DIRECTIONS {
+                    let q = add(&u, &dir);
+
+                    if q == p {
+                        continue;
+                    }
+
+                    if color.get(&q).is_some_and(|j| *j != i) {
+                        break 'outer true;
+                    }
+
+                    if !close_list.contains(&q)
+                        && color_grid.is_walkable(walkable, &q)
+                        && color_grid.is_inside_margin(&q, 1)
+                    {
+                        open_list.push(q);
+                        color.insert(q, i);
+                    }
+                }
+
+                close_list.insert(u);
+            }
+
+            false
+        };
+
+        if reachable {
+            filled.insert(p);
+            for dir in DIRECTIONS {
+                let q = add(&p, &dir);
+                open_list.push(q);
+            }
+        }
+    }
+
+    filled.len()
+}
+
+#[test]
+fn it_should_compute_pocket_size_round_small_hole() {
+    let color_grid = Grid::<Color>::from(
+        r#"
+_####   _
+ #  #
+ #  #
+ ####
+"#,
+    );
+
+    assert_eq!(
+        get_pocket_size(&color_grid, Color::Color1, &Point { x: 3, y: 1 }),
+        4
+    );
+}
+
+#[test]
+fn it_should_compute_pocket_size_round_hole() {
+    let color_grid = Grid::<Color>::from(
+        r#"
+_#####   _
+ #....#
+ #....#
+ #####
+"#,
+    );
+
+    assert_eq!(
+        get_pocket_size(&color_grid, Color::Color1, &Point { x: 3, y: 1 }),
+        8
+    );
+}
+
+#[test]
+fn it_should_compute_pocket_size_open() {
+    let color_grid = Grid::<Color>::from(
+        r#"
+_#####...
+ #.......
+ #.......
+ ########
+"#,
+    );
+
+    assert!(get_pocket_size(&color_grid, Color::Color1, &Point { x: 3, y: 1 }) > 100);
+}
+
+#[test]
+fn it_should_compute_pocket_size_loop() {
+    let color_grid = Grid::<Color>::from(
+        r#"
+######   _
+#....#
+#.##.#
+#....#
+######
+"#,
+    );
+
+    assert_eq!(
+        get_pocket_size(&color_grid, Color::Color1, &Point { x: 3, y: 1 }),
+        10
+    );
+}
+
+#[test]
+fn it_should_compute_pocket_size_dead_end() {
+    let color_grid = Grid::<Color>::from(
+        r#"
+###########
+##  #######
+##   ######
+###########
+"#,
+    );
+
+    assert_eq!(
+        get_pocket_size(&color_grid, Color::Color1, &Point { x: 3, y: 1 }),
+        4
+    );
+}
+
+#[test]
+fn it_should_compute_pocket_size_dead_end_2() {
+    let color_grid = Grid::<Color>::from(
+        r#"
+###########
+##....#####
+##.......##
+###########
+"#,
+    );
+
+    assert_eq!(
+        get_pocket_size(&color_grid, Color::Color1, &Point { x: 3, y: 1 }),
+        8
+    );
+}
+
+#[test]
+fn it_should_compute_pocket_size_dead_end_3() {
+    let color_grid = Grid::<Color>::from(
+        r#"
+###########
+##  #######
+##
+###########
+"#,
+    );
+
+    assert_eq!(
+        get_pocket_size(&color_grid, Color::Color1, &Point { x: 3, y: 1 }),
+        4
+    );
+}
+
+#[test]
+fn it_should_compute_pocket_size_dead_end_4() {
+    let color_grid = Grid::<Color>::from(
+        r#"
+#########
+##....###
+##.....##
+##.....##
+#.....###
+###..####
+#########
+"#,
+    );
+
+    assert_eq!(
+        get_pocket_size(&color_grid, Color::Color1, &Point { x: 3, y: 1 }),
+        20
+    );
+}