[Haskell-cafe] For Euler 25; What is the first term in the Fibonacci sequence to contain 1000 digits?; the following seems to work.

[KC]

For Euler 25; What is the first term in the Fibonacci sequence to
contain 1000 digits?; the following seems to work.


-- For number of digits being 5 or more.
fibNdigits :: Int -> Int
fibNdigits nDigits = floor (((fromIntegral nDigits) - 1.0) / (logBase
10 phi)) + 2
  where
    sq5 = sqrt 5 :: Double
    phi = (1 + sq5) / 2


-- 
--
Regards,
KC