Population count: Difference between revisions
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Not a robot (talk | contribs) (Add BCPL) |
m (→{{header|Haskell}}: Tidied, applied Ormolu.) |
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Or, if we want to write our own popCount, perhaps something like: |
Or, if we want to write our own popCount, perhaps something like: |
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<lang haskell>import Data. |
<lang haskell>import Data.Bifoldable (biList) |
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| ⚫ | |||
import Data.Tuple (swap) |
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import Data.Bool (bool) |
import Data.Bool (bool) |
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import Data.List (partition, unfoldr) |
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| ⚫ | |||
--------------------- POPULATION COUNT ------------------- |
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popCount :: Int -> Int |
popCount :: Int -> Int |
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popCount = |
popCount = sum . unfoldr go |
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where |
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sum . unfoldr ((bool Nothing . Just . swap . flip quotRem 2) <*> (0 <)) |
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go = |
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( bool Nothing |
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. Just |
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. swap |
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. flip quotRem 2 |
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) |
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<*> (0 <) |
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--------------------------- TEST ------------------------- |
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main :: IO () |
main :: IO () |
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main = |
main = |
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mapM_ putStrLn $ |
mapM_ putStrLn $ |
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zipWith |
zipWith |
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(\k xs -> |
(\k xs -> concat [k, ":\n", show xs, "\n"]) |
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["Population count of powers of 3", "evil", "odious"] |
["Population count of powers of 3", "evil", "odious"] |
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((popCount . (3 ^) <$> [0 .. 29]) : |
( (popCount . (3 ^) <$> [0 .. 29]) : |
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biList (partition (even . popCount) [0 .. 59]) |
biList (partition (even . popCount) [0 .. 59]) |
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)</lang> |
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{{Out}} |
{{Out}} |
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<pre>Population count of powers of 3: |
<pre>Population count of powers of 3: |
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