problem104.rb

LOG1 = Math.log(GOLDEN_RATIO, 10)
LOG2 = Math.log(Math.sqrt(5), 10)

def problem104
  n = 2
  fn1 =1
  fn2 = 1
  while true
    n += 1
    fn = (fn1 + fn2) % 10**9
    fn2 = fn1
    fn1 = fn
    if pandigital?(fn)
      val = n*LOG1 - LOG2
      if pandigital?((10**(val - val.floor + 8)).floor)
        break
      end
    end
  end
  n
end