gistfile1.hs

import Control.Applicative
import Control.Monad
import qualified Data.Map as M
import qualified Data.Set as S
import Data.Maybe
import Data.List
import Text.Printf

nextRng b c r prev = (b * prev + c) `mod` r

smartSolve :: TestCase -> Integer
smartSolve (TestCase n k a b c r) =
  cyclingList !! (fromIntegral ((n - k - 1) `mod` (k + 1)))
	where
		startList = genericTake k (iterate (nextRng b c r) a)
		positionMap = M.fromList $ filter ((<= k) . snd) $ zip [1..] startList
		cyclingList = reverse $ snd $ mapAccumL getNumber (S.fromList [0..k]) [k, k-1..0]
		getNumber availableNums pos =
			let maxNum = S.findMax availableNums; next =
				case M.lookup pos positionMap of
					Just x -> if S.member x availableNums then x else maxNum
					Nothing -> maxNum
			in (S.delete next availableNums, next)

data TestCase =
  TestCase Integer Integer Integer Integer Integer Integer
	deriving Show

main = do
	n <- readLn
	forM_ [1..n] $ \i -> do
		[n, k] <- readIntegers
		[a, b, c, r] <- readIntegers
		putStrLn ("Case #" ++ (show i) ++ ": " ++ (show $ smartSolve $ TestCase n k a b c r))
	where
		readIntegers = ((map read) . words) <$> getLine