licenses.rb

licenses = [ 20,5,5,1,1,10,1,10,1,1,1,1,1,1,1].sort.reverse

# simulates a sorted SQL select operation on the license table.
def licenses.pop_eq_to_or_less_than(i)
  idx = 0
  to_slice = -1
  for x in self
    if x <= i
        to_slice = idx
        break
    end
    idx = idx + 1
  end
  self.slice(idx)
end

# number of users
enum = 18.times
offset = 0
remaining_seats = 18

a = enum.map do |x|
  offset = offset - 1 unless offset < 1
  if offset < 1
    l = licenses.pop_eq_to_or_less_than(remaining_seats)
    raise "No More Licenses" if l.nil?
    offset = offset + l
    remaining_seats = remaining_seats - l
    l
  end
end.compact.to_a

p a

output.txt

[10, 5, 1, 1, 1]