Given an array of INTs, calculate each INT's percentage contribution towards the sum of all INTs. Rounding needs to be done so that output floats can sum to a perfect 100%

gistfile1.rb

def percentagerize(collection, result=[], remainder=1)
  collection = Array(collection)

  return result if collection.count == 0

  denominator = collection.inject(:+)

  percent = 0.0
  unless denominator == 0
    percent = (remainder * (collection[0] / denominator.to_f)).round(4)
    remainder -= percent
  end

  percentagerize(collection[1..-1], result << percent, remainder)
end

puts percentagerize([0, 1, 3, 1, 0, 0]).inspect
puts percentagerize([0, 1, 3, 1, 0]).inspect
puts percentagerize([1, 1, 3, 1, 0]).inspect
puts percentagerize([]).inspect
puts percentagerize(1).inspect
puts percentagerize(nil).inspect