19 lines
435 B
Haskell
19 lines
435 B
Haskell
{-
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n! means n x (n - 1) x ... x 3 x 2 x 1.
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For example, 10! = 10 x 9 x ... x 3 x 2 x 1 = 3628800,
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and the sum of the digits in the number 10! is 3 + 6 + 2 + 8 + 8 + 0 + 0 = 27.
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Find the sum of the digits in the number 100!.
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-}
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import Data.Char (digitToInt)
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read' :: Integer -> String
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read' = show
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main :: IO ()
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main = do
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print $ "Answer: " <> show ans
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ans :: Int
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ans = sum $ map digitToInt $ read' $ product [1..100]
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