Submission #47295075

---

Source Code Expand

{-# OPTIONS_GHC -O2 #-}

-- copy of #32837196

module Main where

import Data.List
import qualified Data.Vector.Unboxed as VU
import qualified Data.Vector.Algorithms.Intro as VAI
{-# RULES "Force inline VAI.sort" VAI.sort = VAI.sortBy compare #-}

main :: IO ()
main = do
  getLine
  zs <- map (map read . words) . lines <$> getContents
  print $ solve zs

solve :: [[Double]] -> Double
solve zs = answer
  where
    zs' = VU.fromList $ map (\[x, y] -> (x, y)) zs
    answer = VU.maximum $ VU.map (calc zs') zs'

calc :: VU.Vector (Double, Double) -> (Double, Double) -> Double
calc zs z@(x, y) = inner 0.0 0 0
  where
    zs' = VU.modify VAI.sort . VU.map angle . VU.filter (/= z) $ zs
    len = VU.length zs'
    angle (x', y') = atan2 (y' - y) (x' - x) * 180.0 / pi
    inner s i j
      | i == len || j == 2 * len = s
      | a == b = inner s i (j + 1)
      | c <= 180.0 = inner (max s c) i (j + 1)
      | otherwise = inner (max s (360.0 - c)) (i + 1) j
      where
        a = zs' VU.! i
        b = if j < len then zs' VU.! j else zs' VU.! (j - len)
        c = b - a + if b > a then 0.0 else 360.0

Submission Info

Compile Error

app/Main.hs:7:1: warning: [-Wunused-imports]
    The import of ‘Data.List’ is redundant
      except perhaps to import instances from ‘Data.List’
    To import instances alone, use: import Data.List()
  |
7 | import Data.List
  | ^^^^^^^^^^^^^^^^

app/Main.hs:10:11: warning: [-Worphans]
    Orphan rule: "Force inline VAI.sort"
                     forall (@(v :: * -> * -> *))
                            (@(m :: * -> *))
                            (@e)
                            ($dPrimMonad_a23j :: Control.Monad.Primitive.PrimMonad m)
                            ($dMVector_a23k :: Data.Vector.Generic.Mutable.Base.MVector v e)
                            ($dOrd_a23l :: Ord e).
                       VAI.sort @m @v @e $dPrimMonad_a23j $dMVector_a23k $dOrd_a23l
                       = VAI.sortBy
                           @m @v @e $dPrimMonad_a23j $dMVector_a23k (compare @e $dOrd_a23l)
   |
10 | {-# RULES "Force inline VAI.sort" VAI.sort = VAI.sortBy compare #-}
   |           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

app/Main.hs:14:3: warning: [-Wunused-do-bind]
    A do-notation statement discarded a result of type ‘String’
    Suggested fix: Suppress this warning by saying ‘_ <- getLine’
   |
14 |   getLine
   |   ^^^^^^^

app/Main.hs:21:30: warning: [-Wincomplete-uni-patterns]
    Pattern match(es) are non-exhaustive
    In a lambda abstraction:
        Patterns of type ‘[Double]’ not matched:
            []
            [_]
            (_:_:_:_)
   |
21 |     zs' = VU.fromList $ map (\[x, y] -> (x, y)) zs
   |                              ^^^^^^^^^^^^^^^^^

Judge Result