day15: minimal code beautifications

day15.py

@@ -10,14 +10,14 @@ def getGrid(lines: List[str], multiply: bool = False) -> Grid:
     for y, l in enumerate(lines):
         for x, v in enumerate(map(int, l)):
             g.set(Coordinate(x, y), v)
-            if multiply:
+            if not multiply:
+                continue
+
             for x2 in range(5):
                 for y2 in range(5):
-                        if x2 == 0 and y2 == 0:
+                    if x2 == y2 == 0:
                         continue
-                        nv = v + x2 + y2
-                        if nv > 9:
-                            nv -= 9
+                    nv = 1 + (v + x2 + y2 - 1) % 9
 
                     g.set(Coordinate(size * x2 + x, size * y2 + y), nv)