[Haskell-cafe] Re: Deleting list of elements from Data.Set
Gracjan Polak
gracjanpolak at gmail.com
Wed Jan 30 09:18:32 EST 2008
Duncan Coutts <duncan.coutts <at> worc.ox.ac.uk> writes:
> Data.List.foldr (Data.Set.delete) s [1,3,5]
> or
> Data.List.foldl' (flip Data.Set.delete) s [1,3,5]
There will be a day when I finally grasp foldr/foldl :)
>
> which is O (n + m * log m) rather than O(m * log n) or if the elements
> you're deleting are already sorted you can shave off the log m using
> Data.Set.fromAscList to get just O (n + m).
Thanks for advice. My data is sorted so the above applies really well.
--
Gracjan
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