Day 18 part 1 solutions

Author: creideiki

Diff for: 18-1.py

@@ -0,0 +1,45 @@
+#!/usr/bin/env python
+
+import numpy
+
+
+class Map:
+    def __init__(self, max_x, max_y, max_z):
+        self.size_x = max_x + 1
+        self.size_y = max_y + 1
+        self.size_z = max_z + 1
+        self.map = numpy.zeros((self.size_x, self.size_y, self.size_z), dtype=numpy.uint8)
+
+    def count_exposed_faces(self):
+        count = 0
+        for x in range(self.size_x):
+            for y in range(self.size_y):
+                for z in range(self.size_z):
+                    if self.map[x, y, z] == 1:
+                        if x == 0 or self.map[x - 1, y, z] == 0:
+                            count += 1
+                        if x == self.size_x - 1 or self.map[x + 1, y, z] == 0:
+                            count += 1
+                        if y == 0 or self.map[x, y - 1, z] == 0:
+                            count += 1
+                        if y == self.size_y - 1 or self.map[x, y + 1, z] == 0:
+                            count += 1
+                        if z == 0 or self.map[x, y, z - 1] == 0:
+                            count += 1
+                        if z == self.size_z - 1 or self.map[x, y, z + 1] == 0:
+                            count += 1
+        return count
+
+
+lines = [list(map(lambda c: int(c), line.strip().split(","))) for line in open('18.input').readlines()]
+
+max_x = max([x for x, _, _ in lines])
+max_y = max([y for _, y, _ in lines])
+max_z = max([z for _, _, z in lines])
+
+obj = Map(max_x, max_y, max_z)
+
+for coords in lines:
+    obj.map[coords[0], coords[1], coords[2]] = 1
+
+print(obj.count_exposed_faces())

Diff for: 18-1.rb

@@ -0,0 +1,53 @@
+#!/usr/bin/env ruby
+
+require 'numo/narray'
+
+class Map
+  def initialize(max_x, max_y, max_z)
+    @size_x = max_x + 1
+    @size_y = max_y + 1
+    @size_z = max_z + 1
+    @map = Numo::UInt8.zeros(@size_x, @size_y, @size_z)
+  end
+
+  def [](x, y, z)
+    @map[x, y, z]
+  end
+
+  def []=(x, y, z, val)
+    @map[x, y, z] = val
+  end
+
+  def count_exposed_faces
+    count = 0
+    @size_x.times do |x|
+      @size_y.times do |y|
+        @size_z.times do |z|
+          next unless @map[x, y, z] == 1
+
+          count += 1 if x == 0 or @map[x - 1, y, z] == 0
+          count += 1 if x == @size_x - 1 or @map[x + 1, y, z] == 0
+          count += 1 if y == 0 or @map[x, y - 1, z] == 0
+          count += 1 if y == @size_y - 1 or @map[x, y + 1, z] == 0
+          count += 1 if z == 0 or @map[x, y, z - 1] == 0
+          count += 1 if z == @size_z - 1 or @map[x, y, z + 1] == 0
+        end
+      end
+    end
+    count
+  end
+end
+
+input = File.read('18.input').lines.map(&:strip).map { |l| l.split(',').map(&:to_i) }
+
+max_x = input.map(&:first).max
+max_y = input.map { |c| c[1] }.max
+max_z = input.map(&:last).max
+
+map = Map.new(max_x, max_y, max_z)
+
+input.each do |coords|
+  map[coords[0], coords[1], coords[2]] = 1
+end
+
+print map.count_exposed_faces, "\n"