結果

問題 No.672 最長AB列
コンテスト
ユーザー torus711
提出日時 2019-01-26 15:36:39
言語 Haskell
(9.10.1)
結果
AC  
実行時間 156 ms / 2,000 ms
コード長 1,188 bytes
コンパイル時間 5,596 ms
コンパイル使用メモリ 179,480 KB
実行使用メモリ 58,368 KB
最終ジャッジ日時 2024-09-16 05:11:08
合計ジャッジ時間 7,973 ms
ジャッジサーバーID
（参考情報） 		judge5 / judge3
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ファイルパターン 結果
sample AC * 3
other AC * 16
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:35:1: warning: [GHC-94817] [-Wtabs]
    Tab character found here, and in 12 further locations.
    Suggested fix: Please use spaces instead.
   |
35 |         plusminus <- map ( \c -> if c == 'A' then 1 else -1 ) <$> getLine
   | ^^^^^^^^

Main.hs:49:14: 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."
   |
49 | maxdiff as = head as - last as
   |              ^^^^
[2 of 2] Linking a.out

ソースコード

diff # 

{-# LANGUAGE BangPatterns #-}
{-# LANGUAGE BinaryLiterals #-}
{-# LANGUAGE MultiWayIf #-}
{-# LANGUAGE NumDecimals #-}
{-# LANGUAGE ScopedTypeVariables #-}
{-# LANGUAGE TupleSections #-}

import Control.Applicative
import Control.Arrow
import Control.Monad
import Control.Monad.ST

import Data.Char
import Data.List
import Data.Maybe

import qualified Data.ByteString.Char8 as B

import Data.Array.ST.Safe
import Data.STRef

import Debug.Trace
import Text.Printf

readInt = readLn :: IO Int
readInts = map ( fst . fromJust . B.readInt ) . B.words <$> B.getLine
readNInts = readInt >>= flip replicateM readInt

which a b f = if f then a else b
mp [ a, b ] = ( a, b )

modifyArray array pos f = writeArray array pos =<< f <$> readArray array pos

main = do
	plusminus <- map ( \c -> if c == 'A' then 1 else -1 ) <$> getLine
	let
		psum = scanl (+) 0 plusminus
	print $ maximum $ map maxdiff $ solve psum

solve psum = runST $ do
	let
		n = succ $ length psum
	occurrences <- newArray ( -n, n ) [] :: ST s ( STArray s Int [Int] )
	forM_ ( zip psum [ 0 .. ] ) $ \( value, pos ) -> 
		modifyArray occurrences value ( pos : )
	getElems occurrences

maxdiff [] = 0
maxdiff as = head as - last as
0