solution.rb

debug = false

inFile = File.open("inFile", "r")
outFile = File.open("outFile", "w")

def satisfied(customer, flavors)
  flavors.each_with_index.any? {|el,index| customer.has_key?(index) ? customer[index] == el : false}
end

def all_be_satisfied(customers, flavors)
  customers.all? {|customer| satisfied customer, flavors}
end

def has_malt(customer)
  customer.has_value?(1)
end

def malt_flavor(customer)
  customer.key(1)-1 # already been checked by has_malt, shifting 1 for correct conversion
end

def satisfy_only_malt(flavor, flavors)
  flavors[flavor] = 1
end

# Case loop
for i in (1..inFile.gets.to_i)

  # flavors
  num_flavors = inFile.gets.to_i

  # customers
  num_customers = inFile.gets.to_i

  flavors = Array.new(num_flavors, 0) # all unmalted
  needs_of_customers = []

  num_customers.times do |i|
    line = inFile.gets.split[1..-1].map {|x| x.to_i}
    customer = Hash[*line]
    needs_of_customers << customer
  end

  result = ""
  while not all_be_satisfied needs_of_customers, flavors && result != "IMPOSSIBLE"
    needs_of_customers.each do |customer|
      if not satisfied(customer, flavors) && has_malt(customer)
        satisfy_only_malt(malt_flavor(customer), flavors)
        break
      elsif (not satisfied(customer, flavors)) && (not has_malt(customer))
        result = "IMPOSSIBLE"
        break
      end
    end
  end

  if result != "IMPOSSIBLE"
    result = flavors.join(" ")
  end


  output = "Case ##{i}: #{result} \n"
  puts output if debug
  outFile.write(output)
end