creideiki
diff --git a/‎11-1.rb
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+122Lines changed: 122 additions & 0 deletions b/‎11-1.rb
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+122Lines changed: 122 additions & 0 deletions
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+#!/usr/bin/env ruby
+
+require 'numo/narray'
+
+class Universe
+  attr_accessor :space, :height, :width, :galaxies
+
+  def initialize(input)
+    @height = input.size
+    @width = input[0].size
+    @space = Numo::UInt8.zeros(@width, @height)
+    @height.times do |y|
+      @width.times do |x|
+        @space[y, x] = 1 if input[y][x] == '#'
+      end
+    end
+    @galaxies = nil
+  end
+
+  def expand!
+    expand_y = []
+    expand_x = []
+
+    @height.times do |y|
+      empty = true
+      @width.times do |x|
+        if @space[y, x] == 1
+          empty = false
+          break
+        end
+      end
+      expand_y << y if empty
+    end
+
+    @width.times do |x|
+      empty = true
+      @height.times do |y|
+        if @space[y, x] == 1
+          empty = false
+          break
+        end
+      end
+      expand_x << x if empty
+    end
+
+    expanded_height = @height + expand_y.size
+    expanded_space = Numo::UInt8.zeros(expanded_height, @width)
+    height_expansions = 0
+    @height.times do |y|
+      @width.times do |x|
+        expanded_space[height_expansions + y, x] =
+          @space[y, x]
+      end
+      if expand_y.include? y
+        @width.times do |x|
+          expanded_space[height_expansions + y + 1, x] = 0
+        end
+        height_expansions += 1
+      end
+    end
+    @space = expanded_space
+    @height = expanded_height
+
+    expanded_width = @width + expand_x.size
+    expanded_space = Numo::UInt8.zeros(expanded_height, expanded_width)
+    width_expansions = 0
+    @width.times do |x|
+      @height.times do |y|
+        expanded_space[y, width_expansions + x] =
+          @space[y, x]
+      end
+      if expand_x.include? x
+        @height.times do |y|
+          expanded_space[y, width_expansions + x + 1] = 0
+        end
+        width_expansions += 1
+      end
+    end
+    @space = expanded_space
+    @width = expanded_width
+  end
+
+  def find_galaxies!
+    @galaxies = []
+    @height.times do |y|
+      @width.times do |x|
+        @galaxies << [y, x] if space[y, x] == 1
+      end
+    end
+  end
+
+  def distances
+    distance = 0
+    @galaxies.permutation(2).map do |pair|
+      distance += (pair[0][0] - pair[1][0]).abs +
+                  (pair[0][1] - pair[1][1]).abs
+    end
+    distance / 2
+  end
+
+  def inspect
+    to_s
+  end
+
+  def to_s
+    s = "<#{self.class}:\n"
+    @height.times do |y|
+      @width.times do |x|
+        s += @space[y, x].to_s
+      end
+      s += "\n"
+    end
+    s += ">"
+  end
+end
+
+input = File.read('11.input').lines.map(&:strip).map(&:chars)
+
+u = Universe.new input
+u.expand!
+u.find_galaxies!
+print u.distances, "\n"