Lah numbers: Difference between revisions
m
→{{header|Haskell}}: An applicative pruning of some minor redundancy.
m (→{{header|Haskell}}: An applicative pruning of some minor redundancy.) |
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Line 467:
<lang haskell>import Text.Printf (printf)
import Control.Monad (when)
import Control.Applicative (liftA2)
factorial
=> n -> n
factorial 0 = 1
factorial n = product [1 .. n]
lah
▲lah :: Integral n => n -> n -> n
:: Integral n
=> n -> n -> n
lah n k
| k == 1 = factorial n
| k == n = 1
| k > n
| k < 1 || n < 1 = 0
| otherwise =
where
f = (*) . factorial <*>
printLah :: (Word, Word) -> IO ()
Line 492 ⟶ 497:
mapM_ (printf "%11d") zeroToTwelve
mapM_ printLah $ (,) <$> zeroToTwelve <*> zeroToTwelve
printf
(maximum $ lah 100 <$> ([0 .. 100] :: [Integer]))
where zeroToTwelve = [0..12]</lang>▼
where
{{out}}
<pre>Unsigned Lah numbers: L(n, k):
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