quick and stupid benchmarking example

Euler12.hs

import Data.List
import System.Environment

{- RE: http://stackoverflow.com/q/6964392/157360

cam@atomos:~/scraps/SO/euler$ ghc -O2 --make Euler12.hs
cam@atomos:~/scraps/SO/euler$ time ./Euler12 1000
842161320

real    0m12.892s
user    0m12.885s
sys     0m0.000s
cam@atomos:~/scraps/SO/euler$ gcc -O3 -lm -o euler12c euler12.c
cam@atomos:~/scraps/SO/euler$ time ./euler12c 
842161320

real    0m12.029s
user    0m11.977s
sys     0m0.000s

-}

triangleNums :: [Int]
triangleNums = scanl1 (+) [1..]

factorCount :: Int -> Int
factorCount n = (+ seed) . (* 2) . length . filter (0 ==) . map (rem n) $ [1..intSqrt]
  where intSqrt = floor . sqrt $ fromIntegral n
        seed = if sqrt (fromIntegral n) == fromIntegral intSqrt
               then -1 
               else 0

euler12 :: Int -> Int
euler12 n = head $ filter ((> n) . factorCount) triangleNums

main = do [n] <- getArgs 
          print . euler12 $ read n