結果

問題 No.583 鉄道同好会
コンテスト
ユーザー pekempey
提出日時 2017-10-28 03:16:37
言語 Haskell
(9.10.1)
結果
TLE  
実行時間 -
コード長 938 bytes
コンパイル時間 6,336 ms
コンパイル使用メモリ 192,000 KB
実行使用メモリ 70,144 KB
最終ジャッジ日時 2024-11-22 00:30:01
合計ジャッジ時間 13,747 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
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ファイルパターン 結果
sample AC * 3
other AC * 15 TLE * 1
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:16:50: 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."
   |
16 |                       then let reachable = dfs ((head . head) g) [] g
   |                                                  ^^^^

Main.hs:16:57: 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."
   |
16 |                       then let reachable = dfs ((head . head) g) [] g
   |                                                         ^^^^

Main.hs:23:39: 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."
   |
23 |     adj1 = map last . filter ((==u) . head) $ g
   |                                       ^^^^

Main.hs:24:16: 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."
   |
24 |     adj2 = map head . filter ((==u) . last) $ g
   |                ^^^^
[2 of 2] Linking a.out

ソースコード

diff # 

import Data.List
import Control.Applicative
import Debug.Trace

main :: IO ()
main = solve <$> (map read . words <$> getLine) <*> (map (map read . words) . lines <$> getContents) >>= putStrLn . yesno

yesno :: Bool -> String
yesno True = "YES"
yesno False = "NO"

solve :: [Int] -> [[Int]] -> Bool
solve [n, m] [] = True
solve [n, m] g = let deg = (map length . group . sort . concat) g
                 in if (all even) deg || (length . filter odd) deg == 2
                      then let reachable = dfs ((head . head) g) [] g
                           in (sort . nub) reachable == (sort . nub . concat) g
                      else False

dfs :: Int -> [Int] -> [[Int]] -> [Int]
dfs u vis g = foldl' f (u:vis) (adj1 ++ adj2)
  where
    adj1 = map last . filter ((==u) . head) $ g
    adj2 = map head . filter ((==u) . last) $ g

    f :: [Int] -> Int -> [Int]
    f vis v
      | v `elem` vis = vis
      | otherwise    = dfs v vis g
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