Re: [Haskell-cafe] how to optmize this code?

On Wed, Mar 30, 2011 at 2:39 PM, Gilberto Garcia wrote:

fkSum :: Int -> [Int] -> Int fkSum a [] = 0 fkSum a (b) = foldl (+) 0 (filter (\x -> isMultiple x b) [1..a])

Daniel Fischer and Yves Parès gave you good suggestions about implementing a different, better algorithm for you problem. However, there's one small thing about your current code. Instead of foldl, you should use foldl' (use "import Data.List"), which is strict in the accumulator. Most of the time you want foldl' instead of foldl. You can learn more about the list folds here [1]. HTH, [1] http://www.haskell.org/haskellwiki/Foldr_Foldl_Foldl%27 -- Felipe.