結果

問題 No.313 π
ユーザー はむ吉🐹
提出日時 2015-12-06 19:15:25
言語 Haskell
(9.10.1)
結果
WA  
実行時間 -
コード長 936 bytes
コンパイル時間 3,975 ms
コンパイル使用メモリ 182,556 KB
実行使用メモリ 6,948 KB
最終ジャッジ日時 2024-09-14 16:01:19
合計ジャッジ時間 5,154 ms
ジャッジサーバーID
（参考情報） 		judge6 / judge1
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 * 1 WA * 1
other AC * 8 WA * 24
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:21:14: warning: [GHC-63394] [-Wx-partial]
    In the use of ‘head’
    (imported from Prelude, 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."
   |
21 |         hp = head ps
   |              ^^^^

Main.hs:23:14: warning: [GHC-63394] [-Wx-partial]
    In the use of ‘tail’
    (imported from Prelude, but defined in GHC.List):
    "This is a partial function, it throws an error on empty lists. Replace it with drop 1, or use pattern matching or Data.List.uncons instead. Consider refactoring to use Data.List.NonEmpty."
   |
23 |         tp = tail ps
   |              ^^^^
[2 of 2] Linking a.out

ソースコード

diff # 

{-# LANGUAGE OverloadedStrings #-}

import qualified Data.ByteString.Lazy.Char8 as C
import Data.Char (isDigit, digitToInt)

-- | Generates as many digits of pi.
-- Based on <http://www.cs.ox.ac.uk/people/jeremy.gibbons/publications/spigot.pdf this article> .
pi_ :: Integral a => [a]
pi_ = g (1, 0, 1, 1, 3, 3) where
    g (q, r, t, k, n, l)
        | 4 * q + r - t < n * t = n : g (10 * q, 10 * (r - n * t), t, k, div (10 * (3 * q + r)) t - 10 * n, l)
        | otherwise = g (q * k, (2 * q + r) * l, t * l, k + 1, div (q * (7 * k + 2) + r * l) (t * l), l + 2)

correct :: C.ByteString -> [Int]
correct = correct_ pi_
correct_ ps ss
    | (not . isDigit) hs = correct_ ps ts
    | digitToInt hs == hp = correct_ tp ts
    | otherwise = [digitToInt hs, hp]
    where
        hp = head ps
        hs = C.head ss
        tp = tail ps
        ts = C.tail ss

main :: IO ()
main = putStrLn . unwords . map show . correct =<< C.getContents
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