oops, we can't walk diagonally

twelve.py

@@ -2,24 +2,41 @@
 from useful import *
 
 a = np.asarray([[ord(c) for c in l] for l in lines(open(0))])
-a = np.arange(9).reshape((3,3)) # todo remove
-e = s = 666
+#a = np.arange(9).reshape((3,3)) # todo remove
+E, S = (0,0), (2,2)
 for (y, x), v in np.ndenumerate(a): # bleh
-    if v == ord('E'):
-        e = (y, x)
+    if v == ord('S'):
+        S = (y, x)
         a[y,x] = ord('a')
-    elif v == ord('S'):
-        s = (y, x)
+    elif v == ord('E'):
+        E = (y, x)
         a[y,x] = ord('z')
 h, w = a.shape
 ic(w,h)
+ic(a[18:23,:5])
 p = np.pad(a, 1, mode='edge')
-comefrom = [[a - p[u:h+u,v:w+v] <= 1 for v in [0,1,2]] for u in [0,1,2]]
+goto = [[p[u:h+u,v:w+v] - a <= 1 for v in range(3)] for u in range(3)]
+#ic(goto)
 s = np.empty((h, w))
 s.fill(h*w) # enough
-tovisit = deque()
+tovisit = deque([S])
 def visits(y, x):
-    return [(u, v) for u in range(y-1,y+2) for v in range(x-1,x+2)
-            if u >= 0 and u < h and v >= 0 and v < w]
-ic(s)
-ic(visits(2,2))
+    return [(y+u-1, x+v-1) for u in range(3) for v in range(3)
+            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)
+done = False
+for i in range(h*w): # still enough
+    if done: break # gah
+    ic(tovisit)
+    ic(s)
+    lenv = len(tovisit)
+    for j in range(lenv):
+        here = tovisit.popleft()
+        if here[0] == E[0] and here[1] == E[1]: # ugh
+            print(i)
+            done = True
+            break
+        if s[here[0],here[1]] > i:
+            s[here[0],here[1]] = i
+            tovisit.extend(visits(*here))