10 lines
336 B
Haskell
10 lines
336 B
Haskell
fn :: Integer -> Integer -> Integer -> Integer
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fn m n max | m == 0 = fn n 1 max
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| sum >= max = 0
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| even sum = sum + fn n sum max
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| odd sum = fn n sum max
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| otherwise = 0
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where sum = m+n
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main = do
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putStrLn "The sum of the even Fibonacci numbers below 4000 is:"
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print (fn 0 0 4000) |