Abundant odd numbers: Difference between revisions
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m (→{{header|AppleScript}}: Minor change to aliquotSum() handler.) |
m (→{{header|Haskell}}: Tidied the Data.Numbers.Primes version – pruned out redundant import.) |
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Or, importing Data.Numbers.Primes (and significantly faster): |
Or, importing Data.Numbers.Primes (and significantly faster): |
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<lang haskell>import Data. |
<lang haskell>import Data.List (group, sort) |
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import Data. |
import Data.Numbers.Primes |
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import Data.Bool (bool) |
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abundantTuple :: Int -> [(Int, Int)] |
abundantTuple :: Int -> [(Int, Int)] |
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abundantTuple n |
abundantTuple n = |
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let x = divisorSum n |
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in [(n, x) | n < x] |
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where |
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x = divisorSum n |
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divisorSum :: Int -> Int |
divisorSum :: Int -> Int |
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foldr -- |
foldr -- |
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(flip ((<*>) . fmap (*)) . scanl (*) 1) |
(flip ((<*>) . fmap (*)) . scanl (*) 1) |
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[1] |
[1] |
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. group |
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. primeFactors |
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main :: IO () |
main :: IO () |
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main = do |
main = do |
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putStrLn "First 25 abundant odd numbers with their divisor sums:" |
putStrLn "First 25 abundant odd numbers with their divisor sums:" |
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mapM_ print $ take 25 ([1,3 ..] >>= abundantTuple) |
mapM_ print $ take 25 ([1, 3 ..] >>= abundantTuple) |
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-- |
-- |
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putStrLn "\n1000th odd abundant number with its divisor sum:" |
putStrLn "\n1000th odd abundant number with its divisor sum:" |
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print $ ([1,3 ..] >>= abundantTuple) !! 999 |
print $ ([1, 3 ..] >>= abundantTuple) !! 999 |
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-- |
-- |
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putStrLn "\nFirst odd abundant number over 10^9, with its divisor sum:" |
putStrLn "\nFirst odd abundant number over 10^9, with its divisor sum:" |
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let billion = 10 ^ 9 :: Int |
let billion = 10 ^ 9 :: Int |
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print $ head ([1 + billion,3 + billion ..] >>= abundantTuple)</lang> |
print $ head ([1 + billion, 3 + billion ..] >>= abundantTuple)</lang> |
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{{Out}} |
{{Out}} |
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<pre>First 25 abundant odd numbers with their divisor sums: |
<pre>First 25 abundant odd numbers with their divisor sums: |
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