プログラマ脳を鍛える数学パズル：Q01

puzzle01.rb

# -- 処理時間計測の自作ライブラリ --
require './process_measure.rb'
# ------------------------------


def search_reversible_num(offset)
  i = offset;

  loop do
    n2 = i.to_s(2)
    n8 = i.to_s(8)
    n10 = i.to_s(10)
    i += 1
    next unless (n2 == n2.reverse) && (n8 == n8.reverse) && (n10 == n10.reverse)
    puts n10
    break
  end
end

measure_do { search_reversible_num(10) }