My Google Code Jam Letter Stamper Solution

gistfile1.rb

# Extend the Array class to provide a
# contains? method and a method 
class Array
  def contains?(item)
    return false if self.nil?
    self.each do |i|
      return true if (item == i)
    end
    return false
  end

  # Calculates the number of required stack operations
  # that fit in with Googles criteria
  def calc_actions
    actions = 0
    stack = Array.new
    self.each do |g|
      if (stack.last != g)
        if (stack.contains? g)
          until(stack.last == g) do
            stack.pop
            actions += 1
          end
        else
          stack.push g
          actions += 1
        end
      end
      actions += 1 # Stamp the last item on stack
    end
    until (stack.last.nil?) do
      stack.pop
      actions += 1
    end
    return actions
  end
end

# Extend the string class to make a conveniance
# method to turn a string into a grade array
class String
  def to_grades()
    return self.scan /A|B|C/
  end
end

# Get the number of tests
t_count = gets.chomp.to_i
ct_count = 1
output = []

# Generate output
until (ct_count > t_count) do
  grades = gets.chomp.upcase.to_grades
  output << "Case \##{ct_count}: #{grades.calc_actions().to_s}"
  ct_count += 1
end

# Output
output.each { |o| puts o }