Advent of Code, day 12

day12.rb

#!/usr/bin/env ruby

# http://adventofcode.com/day/12

require "json"

# part 1

puts File.read("input").scan(/-?\d+/).map(&:to_i).reduce(0, &:+)

# part 2

def sum_of_numbers(o)
  case o
  when Array
    o.map do |e|
      sum_of_numbers(e)
    end.reduce(0, &:+)
  when Hash
    if o.values.include?("red")
      0
    else
      sum_of_numbers(o.values)
    end
  when Numeric
    o
  else
    0
  end
end

h = JSON.load(File.read("input"))
puts sum_of_numbers(h)