42 lines
1.5 KiB
Haskell
Executable File
42 lines
1.5 KiB
Haskell
Executable File
#! /usr/bin/env stack
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-- stack --resolver lts-12.20 --install-ghc script
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{-# LANGUAGE ViewPatterns, TupleSections #-}
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module Main where
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import Control.Arrow ((***), (&&&))
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import Data.Bifunctor (Bifunctor, bimap)
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import Data.Function (on)
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import Data.Maybe (catMaybes)
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import qualified Data.Array as A
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import qualified Data.List as L
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import qualified Data.Set as S
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import Debug.Trace
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main :: IO ()
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main = interact $ (. (map parseLine . lines)) $ \points ->
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let limits = (both minimum &&& both maximum) $ (map fst &&& map snd) points
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((minX,minY),(maxX,maxY)) = limits
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closest = A.array limits $ map (\p -> (p, findClosest p)) (A.range limits)
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dist (x0,y0) (x1,y1) = abs (x0-x1) + abs (y0-y1)
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findClosest pt
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| ((d0,pt0):(d1,_):_) <- L.sortBy (compare `on` fst) (map (dist pt &&& id) points)
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, d0 < d1 = Just pt0
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| otherwise = Nothing
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infinite = S.fromList $ catMaybes $
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[ closest A.! ix
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| ix <- map (,minY) [minX..maxX-1]
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++ map (maxX,) [minY..maxY-1]
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++ map (,maxY) [minX+1..maxX]
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++ map (minX,) [minY+1..maxY]
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]
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finite = S.fromList points `S.difference` infinite
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areas = [ (p, length $ filter (== Just p) (A.elems closest)) | p <- S.toList finite ]
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in traceShow closest $ unlines $ map show $ L.sortBy (compare `on` snd) areas
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parseLine :: String -> (Int, Int)
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parseLine (break (==',') -> (read -> x, ',':' ':(read -> y))) = (x, y)
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both :: Bifunctor p => (a -> b) -> p a a -> p b b
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both f = bimap f f
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