1{- 2/* $NetBSD: lru.hs,v 1.1 2006/10/09 12:32:46 yamt Exp $ */ 3 4/*- 5 * Copyright (c)2005 YAMAMOTO Takashi, 6 * All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 */ 29-} 30 31import System.Environment 32import System.IO 33import List 34import Maybe 35 36contain x xs = isJust $ find (== x) xs 37 38do_lru1 npg n q qlen [] = (reverse n, q) 39do_lru1 npg n q qlen rs@(r:rs2) = 40 if contain r q then 41 let 42 nq = delete r q 43 in 44 do_lru1 npg n (r:nq) qlen rs2 45 else if qlen < npg then 46 do_lru1 npg (r:n) (r:q) (qlen+1) rs2 47 else 48 let 49 nq = take (qlen-1) q 50 in 51 do_lru1 npg (r:n) (r:nq) qlen rs2 52 53do_lru npg rs = fst $ do_lru1 npg [] [] 0 rs 54 55main = do 56 xs <- getContents 57 args <- getArgs 58 let 59 ls = lines xs 60 npgs::Int 61 npgs = read $ args !! 0 62 pgs::[Int] 63 pgs = map read ls 64 mapM_ print $ do_lru npgs pgs 65