Fermat numbers: Difference between revisions
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<lang haskell>import Data.Numbers.Primes (primeFactors) |
<lang haskell>import Data.Numbers.Primes (primeFactors) |
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import Data.Bool (bool) |
import Data.Bool (bool) |
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fermat :: Integer -> Integer |
fermat :: Integer -> Integer |
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fermat = succ . (2 ^) . (2 ^) |
fermat = succ . (2 ^) . (2 ^) |
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fermats :: [Integer] |
fermats :: [Integer] |
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fermats = fermat <$> [0 ..] |
fermats = fermat <$> [0 ..] |
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| ⚫ | |||
| ⚫ | |||
main :: IO () |
main :: IO () |
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main = |
main = |
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"Factors of first 7:" |
"Factors of first 7:" |
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show |
show |
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showFactors |
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((bool "(prime)" . show) <*> ((1 <) . length)) |
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primeFactors |
primeFactors |
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(take 7 fermats) |
(take 7 fermats) |
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] |
] |
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------------------------- |
------------------------- DISPLAY -------------------------- |
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fTable :: String -> (a -> String) -> (b -> String) -> (a -> b) -> [a] -> String |
fTable :: String -> (a -> String) -> (b -> String) -> (a -> b) -> [a] -> String |
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fTable s xShow fxShow f xs = |
fTable s xShow fxShow f xs = |
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where |
where |
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rjust n c = drop . length <*> (replicate n c ++) |
rjust n c = drop . length <*> (replicate n c ++) |
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w = maximum (length . xShow <$> xs) |
w = maximum (length . xShow <$> xs) |
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showFactors :: [Integer] -> String |
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showFactors x |
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| 1 < length x = show x |
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| otherwise = "(prime)"</lang> |
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{{Out}} |
{{Out}} |
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<pre>First 10 Fermats: |
<pre>First 10 Fermats: |
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