Difference between revisions of "Talk:99 questions/Solutions/31"
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(→And something as simple as this one...: new section) |
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| otherwise = (n `rem` x) /= 0 && isPrime' (x+1) n |
| otherwise = (n `rem` x) /= 0 && isPrime' (x+1) n |
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</haskell> |
</haskell> |
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+ | |||
+ | == And something as simple as this one... == |
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+ | |||
+ | isPrime :: Int -> Bool |
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+ | isPrime n = all (\x -> n `mod`x /= 0) [2..sqr] |
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+ | where sqr = floor (sqrt (fromIntegral n :: Double)) |
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+ | |||
+ | -- Assuming that a number is not a prime if he is divisible by any number between 2 and his sqrt |
Revision as of 11:14, 14 October 2013
Does something as simple but as dump as this should be on the wiki ?
isPrime :: Int -> Bool
isPrime n | n <= 1 = False
isPrime n = isPrime' 2 n
where isPrime' x n | x*x > n = True
| otherwise = (n `rem` x) /= 0 && isPrime' (x+1) n
And something as simple as this one...
isPrime :: Int -> Bool isPrime n = all (\x -> n `mod`x /= 0) [2..sqr] where sqr = floor (sqrt (fromIntegral n :: Double))
-- Assuming that a number is not a prime if he is divisible by any number between 2 and his sqrt