Solution for Day 03

day_03/second.rb

@@ -0,0 +1,23 @@
+# frozen_string_literal: true
+
+input = File.readlines './input'
+width = input.first.strip.size
+output = []
+
+[
+  { r: 1, d: 1 },
+  { r: 3, d: 1 },
+  { r: 5, d: 1 },
+  { r: 7, d: 1 },
+  { r: 1, d: 2 }
+].each do |dir|
+  count = 0
+  input.each_with_index.select do |_, i|
+    i % dir[:d] == 0
+  end.each_with_index do |row, i|
+    count += 1 if row.first[i * dir[:r] % width] == '#'
+  end
+  output << count
+end
+
+puts output.inject :*