On Mon, 24 May 2010 15:27:03 +0200
Lafras Uys
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I want to remove the biggest element from a list:
withoutBiggest (x:xs) = withoutBiggestImpl (biggest x xs) [] (x:xs) where biggest :: (Ord a) => a -> [a] -> a biggest big [] = big biggest big (x:xs) = if x > big then biggest x xs else biggest big xs withoutBiggestImpl :: (Eq a) => a -> [a] -> [a] -> [a] withoutBiggestImpl big before (x:xs) = if big == x then before ++ xs else withoutBiggestImpl big (before ++ [x]) xs
Works, but I am a little concerned that this is slower than needed, because the list has to be iterated twice.
Can this be done faster?
import Data.List init sort xs
or
import Data.List delete (maximum xs) xs
I see. I would think, the first solution takes still to much time because it needs to sort the list. Is "delete" a fast operation (O(1))? or does it internally traverse the list? Thanks! Nathan