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September 2017 Update

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Ingy döt Net 2017-09-23 10:01:46 +02:00
parent bba7bfd280
commit ba8067c3b7
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Task/Closest-pair-problem/Haskell/closest-pair-problem-1.hs
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@ -1,16 +1,23 @@
import Data.List
import System.Random
import Control.Monad
import Control.Arrow
import Data.Ord
import Data.List (minimumBy, tails, unfoldr, foldl1') --'
vecLeng [[a,b],[p,q]] = sqrt $ (a-p)^2+(b-q)^2
import System.Random (newStdGen, randomRs)
findClosestPair = foldl1' ((minimumBy (comparing vecLeng). ). (. return). (:)) .
concatMap (\(x:xs) -> map ((x:).return) xs) . init . tails
import Control.Arrow ((&&&))
import Data.Ord (comparing)
vecLeng [[a, b], [p, q]] = sqrt $ (a - p) ^ 2 + (b - q) ^ 2
findClosestPair =
foldl1'' ((minimumBy (comparing vecLeng) .) . (. return) . (:)) .
concatMap (\(x:xs) -> map ((x :) . return) xs) . init . tails
testCP = do
g <- newStdGen
let pts :: [[Double]]
pts = take 1000. unfoldr (Just. splitAt 2) $ randomRs(-1,1) g
print . (id &&& vecLeng ) . findClosestPair $ pts
g <- newStdGen
let pts :: [[Double]]
pts = take 1000 . unfoldr (Just . splitAt 2) $ randomRs (-1, 1) g
print . (id &&& vecLeng) . findClosestPair $ pts
main = testCP
foldl1'' = foldl1'