file = open("test.graph", 'r')


def parse(fd)
  h, k = {}, ""
  fd.each do |l|
    l.chomp!
    case l
      when /^[0-9]+->$/
        k = l.delete("->")
        h[k] = []
      when /^([0-9]+;)+$/
        arr = l.split(";")
        arr.each do |i|
          h[k] << i
        end
      else
        puts "in other #{l}"
        next
    end
  end
  h
end

parse(file).each do |key,value|
  value.each do |item|
    puts "#{key}->#{item};"
  end
end