結果

問題 No.482 あなたの名は
コンテスト
ユーザー alpha_virginis
提出日時 2017-02-18 00:18:28
言語 Haskell
(9.10.1)
結果
AC  
実行時間 598 ms / 2,000 ms
コード長 2,519 bytes
記録
記録タグの例:
初AC ショートコード 純ショートコード 純主流ショートコード 最速実行時間
コンパイル時間 6,097 ms
コンパイル使用メモリ 181,056 KB
実行使用メモリ 116,096 KB
最終ジャッジ日時 2024-12-30 03:06:07
合計ジャッジ時間 15,588 ms
ジャッジサーバーID
（参考情報） 		judge2 / judge5
このコードへのチャレンジ
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ファイルパターン 結果
sample AC * 3
other AC * 28
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 )
[2 of 2] Linking a.out

ソースコード

diff #
raw source code 

{-# LANGUAGE OverloadedStrings #-}
module Main where

import Data.Maybe
import qualified Data.ByteString.Char8 as C
import Control.Monad(forM_)
import Data.Int
import Data.List
import Data.Array
import Data.Word
import Data.Bits

yes :: C.ByteString
yes = "YES"

no :: C.ByteString
no = "NO"

getInts :: IO [Int]
getInts = do
  ss <- C.getLine
  return $ map (fst . fromJust . C.readInt) $ C.words ss

getIntss :: Int -> IO [[Int]]
getIntss 0 = return []
getIntss n = do
  xs <- getInts
  xss <- getIntss (n - 1)  
  return $ xs : xss

-- end standard template --

-- begin tree template -- 
data Tree a = Node (Tree a) a (Tree a)

initTree :: a -> Tree a
initTree x = Node (initTree x) x (initTree x)

update' :: Int -> (a -> a) -> Tree a -> Tree a
update' 0 f (Node l x r) = Node l (f x) r
update' i f (Node l x r)
  | mod i 2 == 1 = Node l' x r
  | otherwise = Node l x r'
    where i' = div i 2
          l' = (update' i' f l)
          r' = (update' (i' - 1) f r)

at :: Tree a -> Int -> a
at (Node _ x _) 0 = x
at (Node l _ r) i
  | mod i 2 == 1 = at l i'
  | otherwise = at r (i' - 1)
    where i' = div i 2
-- end tree template --

-- begin boolean flags template --
type Flags = Tree Word64
initFlags :: Flags
initFlags = initTree 0

setFlag :: Int -> Flags -> Flags
setFlag i flags = update' (i `shiftR` 6) f flags
  where f = \x -> x .|. (1 `shiftL` (i .&. 0x3f))

getFlag :: Int -> Flags -> Bool
getFlag i flags = ((flags `at` (i `shiftR` 6)) .&. (1 `shiftL` (i .&. 0x3f))) /= 0
-- end boolean flags template --

main :: IO ()
main = do
  [n,k] <- getInts
  xs <- getInts
  let ss = solve n k xs
  C.putStrLn ss

solve :: Int -> Int -> [Int] -> C.ByteString
solve n k xs = if diff <= k && mod diff 2 == mod k 2 then yes else no
  where
    xs' = listArray (1,n) xs
    visited = initFlags
    (_, count) = f n xs' visited 0
    diff = count

f :: Int -> Array Int Int -> Flags -> Int -> (Flags, Int)
f 0 xs visited count = (visited, count)
f i xs visited count = if getFlag (toEnum i) visited == True
                       then f (i - 1) xs visited  count
                       else f (i - 1) xs visited' (count + count')
                         where
                           (visited', count') = g i i xs visited 0

g :: Int -> Int -> Array Int Int -> Flags -> Int -> (Flags, Int)
g s i xs visited count = if (xs ! i) == s
                         then (visited', count)
                         else g s (xs ! i) xs visited' (count + 1)
                           where visited' = setFlag i visited
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