Coding Interview Practice (Dec. 24)

merge.rb

class Array
  def merge_with other
    res = []
    until self.empty? or other.empty?
      a, b = self.shift, other.shift
      if a == b
        res << a
      elsif a < b
        res << a
        other.unshift b
      else # a > b
        res << b
        self.unshift a
      end
    end
    res += self + other
  end

  def merge ; self.reduce :merge_with end
end

puts [[0, 5, 8, 9], [1, 2, 7], [10]].merge.inspect