Solved part 1

day03/solution.rb

@@ -0,0 +1,20 @@
+#!/bin/env ruby
+
+#part 1
+report = File.readlines('./input').map(&:strip)
+masks = []
+report[0].length.times{ masks.push(2 ** _1) }
+report.map!{ _1.to_i(2) }
+gamma = 0
+
+masks.each do |mask|
+    if report.map{ mask & _1 }.reject(&:zero?).count > report.count / 2
+        gamma += mask
+    end
+end
+
+epsilon = gamma ^ masks.sum
+puts "Gamma is #{gamma}"
+puts "Epsilon is #{epsilon}"
+puts "Power is #{gamma * epsilon}"
+