From 772dda0bbc10a92889e460ae786677fdfe6dc53c Mon Sep 17 00:00:00 2001
From: Andrew Ekstedt <andrew.ekstedt@gmail.com>
Date: Sat, 17 Dec 2022 22:35:10 -0800
Subject: [PATCH] day 18 python fix a flood fill bug

not sure how this ever worked
---
 day18/sol.py | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/day18/sol.py b/day18/sol.py
index f71ed65..780fd58 100644
--- a/day18/sol.py
+++ b/day18/sol.py
@@ -53,11 +53,10 @@ def flood(lava, border):
         x |= roll(a, 1, +1)
         x |= roll(a, 2, -1)
         x |= roll(a, 2, +1)
-        x = x & ~border
-        x = x & ~lava
-        if (a == x).all():
-            a |= border
+        x &= ~lava
+        b = a | x
+        if (a == b).all():
             return a
-        a = x
+        a = b
 
 solve()