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Arithmetic derivative: Difference between revisions
Initial Haskell version.
Thundergnat (talk | contribs) m (Thundergnat moved page Arithmetic Derivative to Arithmetic derivative: Capitalization policy) |
(Initial Haskell version.) |
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Line 209:
108 43 1 124 22 45 32 140 1 123
20 96 34 49 24 272 1 77 75 140
D(10^1 ) / 7 = 1
D(10^2 ) / 7 = 20
D(10^3 ) / 7 = 300
D(10^4 ) / 7 = 4000
D(10^5 ) / 7 = 50000
D(10^6 ) / 7 = 600000
D(10^7 ) / 7 = 7000000
D(10^8 ) / 7 = 80000000
D(10^9 ) / 7 = 900000000
D(10^10) / 7 = 10000000000
D(10^11) / 7 = 110000000000
D(10^12) / 7 = 1200000000000
D(10^13) / 7 = 13000000000000
D(10^14) / 7 = 140000000000000
D(10^15) / 7 = 1500000000000000
D(10^16) / 7 = 16000000000000000
D(10^17) / 7 = 170000000000000000
D(10^18) / 7 = 1800000000000000000
D(10^19) / 7 = 19000000000000000000
D(10^20) / 7 = 200000000000000000000
</pre>
=={{header|Haskell}}==
<lang haskell>import Control.Monad (forM_)
import Data.List (intercalate)
import Data.List.Split (chunksOf)
import Math.NumberTheory.Primes (factorise, unPrime)
import Text.Printf (printf)
-- The arithmetic derivative of a number, which is assumed to be non-negative.
arithderiv_ :: Integer -> Integer
arithderiv_ 0 = 0
arithderiv_ n = foldr step 0 $ factorise n
where step (p, v) s = s + n `quot` unPrime p * fromIntegral v
-- The arithmetic derivative of any integer.
arithderiv :: Integer -> Integer
arithderiv n | n < 0 = negate $ arithderiv_ (negate n)
| otherwise = arithderiv_ n
printTable :: [Integer] -> IO ()
printTable = putStrLn
. intercalate "\n"
. map unwords
. chunksOf 10
. map (printf "%5d")
main :: IO ()
main = do
printTable [arithderiv n | n <- [-99..100]]
putStrLn ""
forM_ [1..20 :: Integer] $ \i ->
let q = 7
n = arithderiv (10^i) `quot` q
in printf "D(10^%-2d) / %d = %d\n" i q n</lang>
{{out}}
<pre>
$ arithderiv
-75 -77 -1 -272 -24 -49 -34 -96 -20 -123
-1 -140 -32 -45 -22 -124 -1 -43 -108 -176
-1 -71 -18 -80 -55 -39 -1 -156 -1 -59
-26 -72 -1 -61 -18 -192 -51 -33 -1 -92
-1 -31 -22 -92 -16 -81 -1 -56 -20 -45
-14 -112 -1 -25 -39 -48 -1 -41 -1 -68
-16 -21 -1 -60 -12 -19 -14 -80 -1 -31
-1 -32 -27 -15 -10 -44 -1 -13 -10 -24
-1 -21 -1 -32 -8 -9 -1 -16 -1 -7
-6 -12 -1 -5 -1 -4 -1 -1 0 0
0 1 1 4 1 5 1 12 6 7
1 16 1 9 8 32 1 21 1 24
10 13 1 44 10 15 27 32 1 31
1 80 14 19 12 60 1 21 16 68
1 41 1 48 39 25 1 112 14 45
20 56 1 81 16 92 22 31 1 92
1 33 51 192 18 61 1 72 26 59
1 156 1 39 55 80 18 71 1 176
108 43 1 124 22 45 32 140 1 123
20 96 34 49 24 272 1 77 75 140
D(10^1 ) / 7 = 1
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