12a

test12

@@ -0,0 +1,5 @@
+Sabqponm
+abcryxxl
+accszExk
+acctuvwj
+abdefghi

twelve.py

@@ -21,7 +21,7 @@ s = np.empty((h, w))
 s.fill(h*w) # enough
 tovisit = deque([S])
 def visits(y, x):
-    return [(y+u-1, x+v-1) for u in range(3) for v in range(3)
+    return [(y+u-1, x+v-1) for (u, v) in [(2, 1), (0, 1), (1, 2), (1, 0)]
             if y+u-1 >= 0 and y+u-1 < h and x+v-1 >= 0 and x+v-1 < w
             and goto[u][v][y,x]]
 #ic(a)