結果

問題 No.59 鉄道の旅
コンテスト
ユーザー aimy
提出日時 2017-07-17 22:28:30
言語 Haskell
(9.10.1)
結果
CE  
(最新)
AC  
(最初)
実行時間 -
コード長 1,862 bytes
コンパイル時間 1,204 ms
コンパイル使用メモリ 173,440 KB
最終ジャッジ日時 2024-11-14 20:07:20
合計ジャッジ時間 1,907 ms
ジャッジサーバーID
（参考情報） 		judge1 / judge3
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コンパイルエラー時のメッセージ・ソースコードは、提出者また管理者しか表示できないようにしております。（リジャッジ後のコンパイルエラーは公開されます）
ただし、clay言語の場合は開発者のデバッグのため、公開されます。

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:8:10: error: [GHC-39999]
    • No instance for ‘Semigroup Int’
        arising from the superclasses of an instance declaration
    • In the instance declaration for ‘Monoid Int’
  |
8 | instance Monoid Int where
  |          ^^^^^^^^^^

Main.hs:64:12: error: [GHC-39999]
    • No instance for ‘Semigroup Int’
        arising from a superclass required to satisfy ‘Monoid Int’,
        arising from a use of ‘fromList’
    • In the expression: fromList maxv (replicate maxv 0)
      In an equation for ‘seg’: seg = fromList maxv (replicate maxv 0)
      In the expression:
        do [_, k] <- map read . words <$> getLine :: IO [Int]
           ws <- map (fst . fromJust . B.readInt) . B.words <$> B.getContents
           let seg = fromList maxv (replicate maxv 0)
           print (freight k seg ws)
   |
64 |  let seg = fromList maxv (replicate maxv 0)
   |            ^^^^^^^^

ソースコード

diff # 

{-# LANGUAGE BangPatterns #-}

import Data.List
import qualified Data.ByteString.Char8 as B
import Data.Maybe
import Data.Monoid

instance Monoid Int where
 mempty = 0
 mappend v w = v + w
 {-# INLINE mempty #-}
 {-# INLINE mappend #-}

data SegTree m =
 Leaf {-# UNPACK #-} !m |
 Node {-# UNPACK #-} !m !(SegTree m) !(SegTree m) deriving (Eq, Show)

type Index = Int
type Size = Int

val :: Monoid m => SegTree m -> m
val (Leaf v) = v
val (Node v _ _) = v
{-# INLINE val #-}

fromList :: Monoid m => Size -> [m] -> SegTree m
fromList 1 [x] = Leaf x
fromList n xs = Node (val left <> val right) left right
 where
  m = div n 2
  (xs1, xs2) = splitAt m xs
  left = fromList m xs1
  right = fromList (n - m) xs2
{-# INLINE fromList #-}

update :: Monoid m => Size -> SegTree m -> Index -> m -> SegTree m
update 1 (Leaf v) 1 x = Leaf (v <> x)
update _ (Leaf _) _ _ = undefined
update n (Node _ l r) i x
 | i <= m = Node (val left <> val r) left r
 | otherwise = Node (val l <> val right) l right
 where
  m = div n 2
  left = update m l i x
  right = update (n - m) r (i - m) x
{-# INLINE update #-}

query :: Monoid m => Size -> SegTree m -> Index -> Index -> m
query 1 (Leaf v) 1 1 = v
query _ (Leaf _) _ _ = undefined
query n (Node v l r) i j
 | (i, j) == (1, n) = v
 | j <= m = query m l i j
 | i > m = query (n - m) r (i - m) (j - m)
 | otherwise = query m l i m <> query (n - m) r 1 (j - m)
 where m = div n 2
{-# INLINE query #-}

maxv = 1000000

main = do
 [_,k] <- map read . words <$> getLine :: IO [Int]
 ws <- map (fst . fromJust . B.readInt) . B.words <$> B.getContents
 let seg = fromList maxv (replicate maxv 0)
 print (freight k seg ws)

freight k seg = val . foldl' (dp k) seg

dp k seg w
 | w < 0 && query maxv seg (abs w) (abs w) /= 0 = update maxv seg (abs w) (-1)
 | w > 0 && query maxv seg w maxv < k = update maxv seg w 1
 | otherwise = seg
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