[Ruby]バブルソート

arr = gets.split.map(&:to_i)

size = arr.size

max = size - 1

(0...max).each do |i|
  max.downto(i+1) { |j|
    if arr[j-1] > arr[j]
      tmp = arr[j-1]
      arr[j-1] = arr[j]
      arr[j] = tmp
    end
  }
end

p arr