結果

問題 No.123 カードシャッフル
ユーザー ducktail
提出日時 2018-02-03 15:30:55
言語 Haskell
(9.10.1)
結果
AC  
実行時間 580 ms / 5,000 ms
コード長 662 bytes
コンパイル時間 2,681 ms
コンパイル使用メモリ 181,044 KB
実行使用メモリ 68,992 KB
最終ジャッジ日時 2024-06-11 15:21:08
合計ジャッジ時間 4,159 ms
ジャッジサーバーID
（参考情報） 		judge3 / judge5
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 * 10
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:12:16: warning: [GHC-63394] [-Wx-partial]
    In the use of ‘head’
    (imported from Data.List, but defined in GHC.List):
    "This is a partial function, it throws an error on empty lists. Use pattern matching or Data.List.uncons instead. Consider refactoring to use Data.List.NonEmpty."
   |
12 | solve [n, m] = head . foldl f [1..n]
   |                ^^^^
[2 of 2] Linking a.out

ソースコード

diff #
プレゼンテーションモードにする

import Control.Applicative ((<$>), (<*>))
import Data.ByteString.Char8 (ByteString)
import qualified Data.ByteString.Char8 as B
import Data.List
import Data.Char (isSpace)
main :: IO ()
main = do
  solve <$> getl (readil B.readInt) <*> getl (readil B.readInt) >>= print
solve :: [Int] -> [Int] -> Int
solve [n, m] = head . foldl f [1..n]
  where
    f ls i = let (as, b:bs) = splitAt (i - 1) ls in b : as ++ bs
getl :: (ByteString -> a) -> IO a
getl f = f <$> B.getLine
readil :: Integral a =>  (ByteString -> Maybe (a, ByteString)) -> ByteString -> [a]
readil f = unfoldr g
  where
    g s = do
      (n, s') <- f s
      return (n, B.dropWhile isSpace s')
הההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההה
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
0