ICPC by Haskell

ICPC2005 Regional, Tokyo の問題Ｂを Haskell で．queue を使ったシミュレーションだけど面倒だから一ターンごとにリスト生成...

 -- Problem B in ACM/ICPC 2005 ASIA Regional Tokyo
 -- 2005/11/04     Brute Force
import Control.Monad
import Debug.Trace
main = getProblems >>= mapM_ (putStrLn.show.solve)
  
getProblems = 
    do
    [m, c, n] <- getNums
    if (n==0 && m==0 && c==0) then return []
       else do
            xs <- replicateM n getEntry
            liftM ((m,c,n,xs):) getProblems
    where 
    getEntry = getNums >> getNums
    getNums = liftM (map read.words) getLine
  
 -- it's better to make each entry of ds the pair of it and its length 
solve (m,c,n,xs) = sl xs 0 (take m $ repeat [])
    where
    sl [] t _ = t
    sl ys t ds = let
                 (hs, ys') = unzip $ map (\x->(head x, tail x)) ys
                 (t', ds') = sl' ds hs
                 in sl (filter (not.(==[])) ys') (t'+t) ds'
    sl' ds = foldl searchOne (0,ds)
    searchOne (t, ds) x = let 
                          p = length $ takeWhile (not.or.map (==x)) ds 
                          ds' =if p<m then take p ds++[filter (not.(==x)) (ds!!p)]++drop (p+1) ds
                               else ds  
                          in insertOne (t+p+1) ds' x
    insertOne t ds x =
        if length (head ds) < c then (t+1, (x:head ds):tail ds)
        else let
             p = length $ takeWhile ((==c).length) ds 
             ds' = if p<m then take p ds++[x:(ds!!p)]++drop (p+1) ds
                   else ds
             p' = length $ takeWhile ((==c).length) ds'
             hds = head ds
             tds = tail ds
             q = p'-1
             tds' =if p'<m then take q tds++[last hds:(tds!!q)]++drop (q+1) tds
                   else tds
             in (t+p+p'+p+5, (x:init hds):tds')