結果

問題 No.265 数学のテスト
コンテスト
ユーザー ともき
提出日時 2015-08-08 03:55:24
言語 Haskell
(9.10.1)
結果
AC  
実行時間 28 ms / 2,000 ms
コード長 2,425 bytes
コンパイル時間 2,152 ms
コンパイル使用メモリ 173,696 KB
実行使用メモリ 13,824 KB
最終ジャッジ日時 2024-11-24 11:25:03
合計ジャッジ時間 2,660 ms
ジャッジサーバーID
（参考情報） 		judge2 / judge1
このコードへのチャレンジ
（要ログイン）
ファイルパターン 結果
sample AC * 4
other AC * 32
権限があれば一括ダウンロードができます
コンパイルメッセージ
Loaded package environment from /home/judge/.ghc/x86_64-linux-9.8.2/environments/default
[1 of 2] Compiling Main             ( Main.hs, Main.o )

Main.hs:36:25: warning: [GHC-63394] [-Wx-partial]
    In the use of ‘tail’
    (imported from Prelude, but defined in GHC.List):
    "This is a partial function, it throws an error on empty lists. Replace it with drop 1, or use pattern matching or Data.List.uncons instead. Consider refactoring to use Data.List.NonEmpty."
   |
36 |     (h,k) = expression (tail r)  -- remove '{'
   |                         ^^^^

Main.hs:37:13: warning: [GHC-63394] [-Wx-partial]
    In the use of ‘tail’
    (imported from Prelude, but defined in GHC.List):
    "This is a partial function, it throws an error on empty lists. Replace it with drop 1, or use pattern matching or Data.List.uncons instead. Consider refactoring to use Data.List.NonEmpty."
   |
37 |     a     = tail k               -- remove '}'
   |             ^^^^

Main.hs:68:67: warning: [GHC-63394] [-Wx-partial]
    In the use of ‘tail’
    (imported from Prelude, but defined in GHC.List):
    "This is a partial function, it throws an error on empty lists. Replace it with drop 1, or use pattern matching or Data.List.uncons instead. Consider refactoring to use Data.List.NonEmpty."
   |
68 | eval (Bibun r)          = do {k <- eval r; return $ zipWith (*) ((tail k) ++ [0]) [1..]}
   |                                                                   ^^^^
[2 of 2] Linking a.out

ソースコード

diff # 

{-# OPTIONS_GHC -O2 -funbox-strict-fields #-}

import Control.Applicative
import Control.Monad.Reader
import qualified Data.List as L

data Exp = Con   !Int
         | Var
         | Mult  !Exp !Exp
         | Plus  !Exp !Exp
         | Bibun !Exp
  deriving (Show)

parse :: String -> Exp
parse s = case expression s of
  (a, "") -> a
  (_, r ) -> error ("remain: " ++ r)

expression :: String -> (Exp, String)
expression s = case r of
  '+' : t -> (Plus h k, a) where (k,a) = expression t
  _        -> (h, r)
  where
    (h,r) = term s

term :: String -> (Exp, String)
term s = case r of
           '*' : t -> (Mult h k, a) where (k,a) = (term t)
           _       -> (h, r)
         where
           (h,r) = factor s

factor :: String -> (Exp, String)
factor ('d' : r) = (Bibun h, a)
  where
    (h,k) = expression (tail r)  -- remove '{'
    a     = tail k               -- remove '}'
factor ('x' : r) = (Var, r)
factor s = (Con x, r)
  where [(x,r)] = reads s


-- list size is constant.
-- eval :: Exp -> [Int]
-- eval (Con a)          = a : [0,0 ..]
-- eval (Var _)          = 0 : 1 : [0,0..]
-- eval (Mult x (Var _)) = 0 : (eval x)
-- eval (Mult x (Con a)) = map (* a) $ eval x
-- eval (Mult (Var _) x) = 0 : (eval x)
-- eval (Mult (Con a) x) = map (* a) $ eval x
-- eval (Mult _ _) = error "mult"

-- eval (Plus l r) = zipWith (+) (eval l) (eval r)
-- eval (Bibun r)  = zipWith (*) (tail $ eval r) [1..]
-- solve :: Int -> String -> [Int]
-- solve max_degree = (take (max_degree+1)) . eval . parse


eval :: Exp -> Reader Int [Int]
eval (Con a)            = do {m <- ask;    return $ take m (a : [0,0 ..])}
eval Var                = do {m <- ask;    return $ take m (0 : 1 : [0,0..])}
eval (Mult x Var)       = do {r <- eval x; return $ 0 : (init r)}
eval (Mult (Con a) x)   = do {r <- eval x; return $ map (* a) r}
eval (Mult Var x)       = do {r <- eval x; return $ 0 : (init r)}
eval (Mult x (Con a))   = do {r <- eval x; return $ map (* a) r}
eval (Mult _ _)         = error "mult"
eval (Plus l r)         = do {a <- eval l; b <- eval r; return $ zipWith (+) a b}
eval (Bibun r)          = do {k <- eval r; return $ zipWith (*) ((tail k) ++ [0]) [1..]}

solve :: Int -> String -> [Int]
solve m s = runReader (eval (parse s)) (m+1)

main :: IO ()
main = do
  n <- read <$> getLine :: IO Int
  d <- read <$> getLine :: IO Int
  s <- getLine
  putStrLn $ foldr (++) ""  (L.intersperse " " (map show (solve d s)))
0