9 lines
330 B
Haskell
9 lines
330 B
Haskell
-- everything here are [Int] or [[Int]], which would overflow
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-- * had it not overrun the stack first *
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ackermann = iterate ack [1..] where
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ack a = s where
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s = a!!1 : f (tail a) (zipWith (-) s (1:s))
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f a (b:bs) = (head aa) : f aa bs where
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aa = drop b a
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main = mapM_ print $ map (\n -> take (6 - n) $ ackermann !! n) [0..5]
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