{- /* $NetBSD: lru.hs,v 1.1 2006/10/09 12:32:46 yamt Exp $ */ /*- * Copyright (c)2005 YAMAMOTO Takashi, * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ -} import System.Environment import System.IO import List import Maybe contain x xs = isJust $ find (== x) xs do_lru1 npg n q qlen [] = (reverse n, q) do_lru1 npg n q qlen rs@(r:rs2) = if contain r q then let nq = delete r q in do_lru1 npg n (r:nq) qlen rs2 else if qlen < npg then do_lru1 npg (r:n) (r:q) (qlen+1) rs2 else let nq = take (qlen-1) q in do_lru1 npg (r:n) (r:nq) qlen rs2 do_lru npg rs = fst $ do_lru1 npg [] [] 0 rs main = do xs <- getContents args <- getArgs let ls = lines xs npgs::Int npgs = read $ args !! 0 pgs::[Int] pgs = map read ls mapM_ print $ do_lru npgs pgs |