1d first fit decreasing bin packing algorithm (see https://en.wikipedia.org/wiki/Bin_packing_problem)

bin_packer.rb

def decreasing_first_fit(elements, max_bin_size)
  bins = [elements.first.class.new]
  elements.sort_by{|e| e.size}.reverse.each do |e|
    found_place = false
    bins.each_with_index do |bin, i|
      if bin.size + e.size <= max_bin_size
        bins[i] += e
        found_place = true
        #puts "found place for #{e} in bin #{i}"
        break
      end
    end
    unless found_place
      bins += [e]
      #puts "creating new bin for #{e}"
    end
  end
  bins
end

a = [Array.new(1,1), Array.new(6,6), Array.new(2,2), Array.new(4,4), Array.new(5,5), Array.new(3,3)]
p decreasing_first_fit(a, 7)
a = ['1', '666666', '22', '4444', '55555', '333']
p decreasing_first_fit(a, 7)

# => [[6, 6, 6, 6, 6, 6, 1], [5, 5, 5, 5, 5, 2, 2], [4, 4, 4, 4, 3, 3, 3]]
# => ["6666661", "5555522", "4444333"]

How do I change the size of the bins and what I want to go into the bins?