http://projecteuler.net/index.php?section=problems&id=99
指数の計算をする代わりにlogの計算をする。
split :: [Char] -> Char -> [Char] -> [[Char]] split [] d s = [s] split (c:cs) d s | c == d = s:(split cs d []) | otherwise = split cs d (s ++ [c]) log_value :: [Char] -> Double log_value s = (fromIntegral y) * (log (fromIntegral x)) where [s1,s2] = split s ',' [] x = read s1 :: Int y = read s2 :: Int greater x y = if snd x > snd y then x else y main = do cs <- readFile "base_exp.txt" print (fst (foldr greater (0,0) (zip [1..] (map log_value (lines cs)))))
