Add utility to draw the state of a hash.

src/advent/util.cr

@@ -54,6 +54,9 @@ struct Tuple(*T)
       { {% for t, i in T %} self[{{i}}].signum, {% end %} }
     {% end %}
   end
+
+  def abs
+  end
 end
 
 struct Number
@@ -62,3 +65,17 @@ struct Number
     self // self.abs
   end
 end
+
+class Hash(K, V)
+  def draw(maps)
+    min_x, max_x = keys.minmax_of &.[0]
+    min_y, max_y = keys.minmax_of &.[1]
+    (max_y-min_y+1).times do |y|
+      (max_x-min_x+1).times do |x|
+        next unless has_key?({x,y})
+        print maps[self[{x,y}]]
+      end
+      puts
+    end
+  end
+end