day 11: numpy (slow :( )

1 files changed, 40 insertions, 0 deletions

diff --git a/11.py b/11.py
new file mode 100644
index 0000000..0c1744b
--- /dev/null
+++ b/11.py
@@ -0,0 +1,40 @@
+from itertools import count
+from utils import open_day
+import numpy as np
+
+with open_day(11) as f:
+    inp = [list(map(int, line.rstrip())) for line in f]
+
+inp = np.array(inp)
+
+def adjacentify(points):
+    tot = np.zeros(points.shape, dtype=int)
+    for dy in (-1, 0, 1):
+        for dx in (-1, 0, 1):
+            if dx == 0 and dy == 0: continue
+            p = points.copy()
+            if dy:
+                p = np.roll(p, dy, 0)
+                p[min(dy, 0), :] = 0
+            if dx:
+                p = np.roll(p, dx, 1)
+                p[:, min(dx, 0)] = 0
+            tot += p
+    return tot
+
+flashes = 0
+for step in count():
+    if step == 100: print(flashes)
+    flashed = np.zeros(inp.shape, dtype=bool)
+    inp += 1
+    while True:
+        flash = (inp > 9) & ~flashed
+        if not flash.any(): break
+        inp += adjacentify(flash * 1)
+        flashed |= flash
+    inp[flashed] = 0
+    s = flashed.sum()
+    flashes += s
+    if s == flashed.shape[0] * flashed.shape[1]:
+        print(step + 1)
+        break