Stuff

class TateYoko  attr_reader :count  def initialize(num = 3)    @num = num    @matrix = Array.new(num+1){Array.new(num+1)}    @all_nums = (1..num).to_a    @count = 0  end  def calc(depth = 0)    line = depth / @num + 1    column = depth % @num + 1    return if line > @num    used_nums = @matrix[line][0, column] + @matrix.transpose[column][0, line]    nums = @all_nums - used_nums    nums.each do |n|      @matrix[line][column] = n      calc(depth + 1)      if depth == @num**2 - 1        @count += 1        show_matrix      end    end  end    def show_matrix    @matrix[1..-1].each {|line| puts line[1..-1].join }    puts  endendtate_yoko = TateYoko.new(3)tate_yoko.calcprint 'total = ', tate_yoko.count