16 lines
512 B
Haskell
16 lines
512 B
Haskell
-- The prime factors of 13195 are 5, 7, 13 and 29. --
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-- What is the largest prime factor of the number 600851475143?
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import ProjectEuler (isPrime)
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maxPrimeFactor :: Integer -> Integer
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maxPrimeFactor n
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| isPrime n = n
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| even n = maxPrimeFactor $ n `div` 2
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| otherwise = maxPrimeFactor $ n `div` head [i | i <- [3,5..], n `mod` i == 0 && isPrime i]
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main = do
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let result = maxPrimeFactor 600851475143
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putStrLn $ "Project Euler, Problem 3\n"
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++ "Answer: " ++ show result
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