WIP: implement part 1

src/days/day12.zig

@@ -169,5 +169,50 @@ const Region = struct {
             }
         }
     }
+
+    pub fn createEmpty(self: Self, allocator: std.mem.Allocator) !EmptyRegion {
+        return try .init(allocator, self.width, self.height);
+    }
+};
+
+const EmptyRegion = struct {
+    grid: [][]bool,
+    filled_spaces: usize,
+
+    allocator: std.mem.Allocator,
+
+    const Self = @This();
+
+    pub fn init(allocator: std.mem.Allocator, width: u8, height: u8) !Self {
+        const h = try allocator.alloc([]bool, height);
+        for (0..height) |i| {
+            const w = try allocator.alloc(u8, width);
+            @memset(w, false);
+            h[i] = w;
+        }
+        return .{
+            .grid = h,
+            .filled_spaces = 0,
+            .allocator = allocator,
+        };
+    }
+
+    pub fn deinit(self: Self) void {
+        for (self.grid) |row| {
+            self.allocator.free(row);
+        }
+        self.allocator.free(self.grid);
+    }
+
+    pub fn fits(self: Self, present: Present) bool {
+        std.debug.assert(self.grid.len > 0);
+        const size = self.grid.len * self.grid[0].len;
+        if ((size - self.filled_spaces) < present.shape.count()) {
+            return false;
+        }
+
+        // TODO: Implementation
+        return false;
+    }
 };