From c27d4e089c7dd2e6c1561c3781634ba5215f71d8 Mon Sep 17 00:00:00 2001
From: nekineki <nekineki@nekineki.net>
Date: Sun, 18 Dec 2022 07:01:48 +0100
Subject: day18

---
 2022/day18.py | 70 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 70 insertions(+)
 create mode 100755 2022/day18.py

(limited to '2022/day18.py')

diff --git a/2022/day18.py b/2022/day18.py
new file mode 100755
index 0000000..92b0583
--- /dev/null
+++ b/2022/day18.py
@@ -0,0 +1,70 @@
+#!/usr/bin/env python3
+
+# import numpy as np
+from functools import reduce
+from re import findall
+from copy import deepcopy
+import sys
+
+# filename = "in/day18.ref"
+filename = "in/day18.pzl"
+data = open(filename).read()
+lines = [line for line in data.rstrip('\n').split('\n')]
+# print(lines)
+
+D = dict()
+
+for line in lines:
+    x,y,z = [int(i) for i in line.split(',')]
+    D[(x,y,z)] = 1
+# print(D)
+
+side_len = 0
+for x,y,z in D.keys():
+    side_len = max(side_len, x, y, z)
+side_len += 1
+# print(side_len)
+
+res1 = 0
+for x,y,z in D.keys():
+    for dx,dy,dz in [(1,0,0), (-1,0,0), (0,1,0), (0,-1,0), (0,0,1), (0,0,-1)]:
+        if (x+dx,y+dy,z+dz) not in D:
+            res1 += 1
+
+
+def bfs(visited):
+    while True:
+        start_len = len(visited)
+        new_visited = set()
+        for x,y,z in visited:
+            for dx,dy,dz in [(1,0,0), (-1,0,0), (0,1,0), (0,-1,0), (0,0,1), (0,0,-1)]:
+                if ((x+dx,y+dy,z+dz) not in visited) and \
+                        -1 <= x+dx < side_len+1 and \
+                        -1 <= y+dy < side_len+1 and \
+                        -1 <= z+dz < side_len+1 and \
+                        ((x+dx,y+dy,z+dz) not in D):
+                    new_visited.add((x+dx,y+dy,z+dz))
+
+        visited = visited.union(new_visited)
+        if len(visited) == start_len:
+            return visited
+
+# O(n**3)
+E = set()
+for x in range(-1, side_len+1):
+    for y in range(-1, side_len+1):
+        for z in range(-1, side_len+1):
+            if max(x,y,z) == side_len or min(x,y,z) == -1:
+                E.add((x,y,z))
+E = bfs(E)
+# print(E)
+
+res2 = 0
+for x,y,z in D.keys():
+    for dx,dy,dz in [(1,0,0), (-1,0,0), (0,1,0), (0,-1,0), (0,0,1), (0,0,-1)]:
+        if (x+dx,y+dy,z+dz) in E:
+            res2 += 1
+
+print('res1:', res1)
+print('res2:', res2)
+
-- 
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