people = {}
purposes = {}

File.read("muenchen-2005.rech").each { |line|
  line.chomp!
  next  if line =~ /^ *(#|$)/       # emacs: /
  name, money, reason = line.split "\t"
  people[name] ||= 0.0
  people[name] += money.to_f
  (purposes[name] ||= []) << reason  if reason =~ /\w/
}

total = people.values.inject { |a,e| a+e }

avg = total / people.size

puts "#{people.size} Leute, #{avg} pro Person (Cashflow: #{total})"

payment = {}

n = people.size
people.each { |na, money|
  (people.keys-[na]).each { |ot|
    next  if money == 0
    pay = money/n

    if na > ot
      other, name = na, ot
      pay = -pay
    else
      name, other = na, ot
    end

    payment[name] ||= {}
    payment[name][other] ||= 0
    payment[name][other] += pay
  }
}


puts
purposes.each { |name, purp|
  unless purp.empty?
    puts "#{name}: #{purp.join ', '}"
  end
}

puts
puts payment.map { |don, v|
  v.map { |rec, n|
    if n == 0
      nil
    elsif n > 0
      "%s -> %s: %.2f" % [rec, don, n]
    else
      "%s -> %s: %.2f" % [don, rec, -n]
    end
  }
}.flatten.compact.sort