array_randomization_comparison.rb

class ArrayRandomizationComparison

  def initialize(array:, method:, runs: 1000)
    @array = array.dup
    @method = method
    @runs = runs

    @comparison_matrix = Array.new(@array.size) {|_| Array.new(@array.size, 0)}
    run
    display
  end

  def run
    @runs.times do
      shuffled_array = @array.dup.send(@method)
      shuffled_array.each_with_index do |value, index|
        @comparison_matrix[index][value] += 1
      end
    end
  end

  def display
    maximum_digits = @runs.to_s.length + 1
    expected_average = (@runs / @array.size.to_f).round(2)
    puts "#{@method} - expected average: #{expected_average} (#{@runs} runs)"
    @comparison_matrix.each_with_index do |row, i|
      row.each_with_index do |value, j|
        distance_from_expected_average = (expected_average - value) * -1
        output_string = distance_from_expected_average.to_s.gsub('.',',').rjust(maximum_digits)
        print("#{output_string};")
      end
      print "\n"
    end
    print "\n"
  end
  
end