10b

junk10

@@ -0,0 +1,10 @@
+FF7FSF7F7F7F7F7F---7
+L|LJ||||||||||||F--J
+FL-7LJLJ||||||LJL-77
+F--JF--7||LJLJ7F7FJ-
+L---JF-JLJ.||-FJLJJ7
+|F|F-JF---7F7-L7L|7|
+|FFJF7L7F-JF7|JL---7
+7-L-JL7||F7|L7F-7F7|
+L.L7LFJ|||||FJL7||LJ
+L7JLJL-JLJLJL--JLJ.L

junkier10

@@ -0,0 +1,10 @@
+┌┌┐┌S┌┐┌┐┌┐┌┐┌┐┌---┐
+└|└┘||||||||||||┌--┘
+┌└-┐└┘└┘||||||└┘└-┐┐
+┌--┘┌--┐||└┘└┘┐┌┐┌┘-
+└---┘┌-┘└┘.||-┌┘└┘┘┐
+|┌|┌-┘┌---┐┌┐-└┐└|┐|
+|┌┌┘┌┐└┐┌-┘┌┐|┘└---┐
+┐-└-┘└┐||┌┐|└┐┌-┐┌┐|
+└.└┐└┌┘|||||┌┘└┐||└┘
+└┐┘└┘└-┘└┘└┘└--┘└┘.└

larger10

@@ -0,0 +1,10 @@
+.F----7F7F7F7F-7....
+.|F--7||||||||FJ....
+.||.FJ||||||||L7....
+FJL7L7LJLJ||LJ.L-7..
+L--J.L7...LJS7F-7L7.
+....F-J..F7FJ|L7L7L7
+....L7.F7||L7|.L7L7|
+.....|FJLJ|FJ|F7|.LJ
+....FJL-7.||.||||...
+....L---J.LJ.LJLJ...

prettier10

@@ -0,0 +1,10 @@
+.┌----┐┌┐┌┐┌┐┌-┐....
+.|┌--┐||||||||┌┘....
+.||.┌┘||||||||└┐....
+┌┘└┐└┐└┘└┘||└┘.└-┐..
+└--┘.└┐...└┘S┐┌-┐└┐.
+....┌-┘..┌┐┌┘|└┐└┐└┐
+....└┐.┌┐||└┐|.└┐└┐|
+.....|┌┘└┘|┌┘|┌┐|.└┘
+....┌┘└-┐.||.||||...
+....└---┘.└┘.└┘└┘...

ten.py

@@ -1,5 +1,7 @@
 #!/usr/bin/env python3
 
+import cv2 as cv
+
 from useful import *
 
 bit = {(-1, 0): 8,
@@ -17,10 +19,8 @@ udlr = {'|': 12, # 1<<3 (u) + 1<<2 (d)
 
 cs = [[udlr[c] for c in l] for l in lines(open(0))]
 ca = np.pad(np.array(cs, dtype=int), 1)
-ic(ca)
 visited = np.zeros(ca.shape, dtype=int)
-pos = tuple(coord for coord in collapse(np.nonzero(ca == 65535)))
-ic(pos)
+pos = next(zip(*np.nonzero(ca == 65535)))
 
 def sub(a, b):
     return (a[0] - b[0], a[1] - b[1])
@@ -42,3 +42,19 @@ while True:
         break
     pos = sub(pos, goto[0])
 print(time // 2)
+
+canvas = np.kron(visited > 0, np.ones((3, 3), dtype='uint8')) # 1 if part of loop...
+for (y, x), bend in np.ndenumerate(ca):
+    canvas[y*3:y*3+3,x*3:x*3+3] &= np.asarray([[False, bend & 8, False], # ...and part of the bend
+                                               [bend & 2, True, bend & 1],
+                                               [False, bend & 4, False]], dtype=bool)
+mask = np.pad(canvas, (1,1))
+for color in count(2): # outside: 2, inside: 3
+    try:
+        empty = next(zip(*np.nonzero(canvas == 0)))
+    except StopIteration: # all filled!
+        break
+    cv.floodFill(canvas, mask, empty, color)
+assert color == 4
+smallvas = canvas[1::3,1::3]
+print(len(np.where(smallvas == 3)[0]))

useful.py

@@ -1,6 +1,6 @@
 #!/usr/bin/env python3
 from functools import cache, reduce
-from itertools import chain, combinations, cycle, dropwhile, groupby, pairwise, permutations, product, takewhile
+from itertools import chain, combinations, count, cycle, dropwhile, groupby, pairwise, permutations, product, takewhile
 from more_itertools import batched, collapse, sliding_window
 from collections import defaultdict, deque
 import re, sys