8 lines
222 B
Haskell
8 lines
222 B
Haskell
import Data.List
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main = print $ entropy "1223334444"
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entropy s =
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sum . map lg' . fq' . map (fromIntegral.length) . group . sort $ s
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where lg' c = (c * ) . logBase 2 $ 1.0 / c
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fq' c = map (\x -> x / (sum c)) c
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