結果

問題 No.482 あなたの名は
コンテスト
ユーザー くれちー
提出日時 2017-02-25 02:47:02
言語 Haskell
(9.10.1)
結果
TLE  
実行時間 -
コード長 1,066 bytes
コンパイル時間 9,484 ms
コンパイル使用メモリ 184,704 KB
実行使用メモリ 192,896 KB
最終ジャッジ日時 2025-01-03 08:37:11
合計ジャッジ時間 57,479 ms
ジャッジサーバーID
（参考情報） 		judge4 / 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 * 3
other AC * 13 TLE * 15
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-9.10.1/environments/default
[1 of 2] Compiling Main             ( Main.hs, Main.o )
Main.hs:9:38: warning: [GHC-63394] [-Wx-partial]
    In the use of ‘tail’
    (imported from Prelude, but defined in GHC.Internal.List):
    "This is a partial function, it throws an error on empty lists. Replace it with 'drop' 1, or use pattern matching or 'GHC.Internal.Data.List.uncons' instead. Consider refactoring to use "Data.List.NonEmpty"."
  |
9 |         t2 = splitAt (pred $ j - i) (tail . snd $ t1)
  |                                      ^^^^

Main.hs:10:14: warning: [GHC-63394] [-Wx-partial]
    In the use of ‘tail’
    (imported from Prelude, but defined in GHC.Internal.List):
    "This is a partial function, it throws an error on empty lists. Replace it with 'drop' 1, or use pattern matching or 'GHC.Internal.Data.List.uncons' instead. Consider refactoring to use "Data.List.NonEmpty"."
   |
10 |         t3 = tail . snd $ t2
   |              ^^^^

[2 of 2] Linking a.out

ソースコード

diff # 

import Data.List (findIndex)

swap :: [a] -> Int -> Int -> [a]
swap xs a b = fst t1 ++ [xs !! pred j] ++ fst t2 ++ [xs !! pred i] ++ t3
    where
        i  = min a b
        j  = max a b
        t1 = splitAt (pred i) xs
        t2 = splitAt (pred $ j - i) (tail . snd $ t1)
        t3 = tail . snd $ t2

rep :: Integral a => [Int] -> [Int] -> Int -> a -> a
rep ds idxs i cnt
    | i > length ds       = cnt
    | ds !! (pred i) == i = rep ds idxs (succ i) cnt
    | otherwise           = rep (swap ds i (idxs !! (pred i))) (swap idxs (ds !! pred i) (ds !! pred (idxs !! pred i))) (succ i) (succ cnt)

solve :: Integral a => Int -> a -> [Int] -> Bool
solve n k ds
    | cnt <= k && even (k - cnt) = True
    | otherwise                  = False
    where
        Just idxs = fmap (map succ) . sequenceA $ (\x -> findIndex (== x)) <$> [1..n] <*> pure ds
        cnt       = rep ds idxs 1 0

main = do
    [n, k] <- map read . words <$> getLine
    ds     <- map read . words <$> getLine
    putStrLn $ case solve n k ds of
        True  -> "YES"
        False -> "NO"
0