From: Christophe Raffalli <christophe.raffalli@univ-savoie.fr>
To: caml-list@inria.fr
Subject: filter on map
Date: Thu, 07 Jun 2007 10:27:52 +0200 [thread overview]
Message-ID: <4667C188.1060408@univ-savoie.fr> (raw)
Dear list members
I just write this piece of code because I wanted filter on map:
module Map_Label = struct
module M = Map.Make(Label)
include M
let filter f m =
M.fold (fun k v m ->
if f k then M.add k v m else m) m M.empty
end
But I am now wondering: this is O(n ln n), isn't there an O(n) implementation (or just a faster
implementation). This code insert the keys in increasing order which is the worst case for balancing
? Just using a "random_fold" should make things better ...
What do you think ?
Cheers,
--
Christophe Raffalli
Université de Savoie
Batiment Le Chablais, bureau 21
73376 Le Bourget-du-Lac Cedex
tél: (33) 4 79 75 81 03
fax: (33) 4 79 75 87 42
mail: Christophe.Raffalli@univ-savoie.fr
www: http://www.lama.univ-savoie.fr/~RAFFALLI
next reply other threads:[~2007-06-07 8:27 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-06-07 8:27 Christophe Raffalli [this message]
2007-06-07 9:11 ` [Caml-list] " Jon Harrop
2007-06-07 13:16 ` Brian Hurt
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