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author | Joe Zhao <ztuowen@gmail.com> | 2015-03-31 23:41:55 +0800 |
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committer | Joe Zhao <ztuowen@gmail.com> | 2015-03-31 23:41:55 +0800 |
commit | a9abc1da41b56edbed00081800382e854d6698d0 (patch) | |
tree | 5265cc1c5296768438b67299afd59bcc57c58f0c /H31.hs | |
parent | 378f6303e8860b7bbca7dea787d584a6728cebf1 (diff) | |
download | h99-a9abc1da41b56edbed00081800382e854d6698d0.tar.gz h99-a9abc1da41b56edbed00081800382e854d6698d0.tar.bz2 h99-a9abc1da41b56edbed00081800382e854d6698d0.zip |
rename to H**, +31 +32 +33 +34 +35 +36
Diffstat (limited to 'H31.hs')
-rw-r--r-- | H31.hs | 15 |
1 files changed, 15 insertions, 0 deletions
@@ -0,0 +1,15 @@ +import System.Random + +isPrime :: Integral a => a -> Bool +isPrime x = and $ fmap ((/=0).(mod x)) [2..(x-1)] + +testn = 10 + +isPrimeT 2 = True +isPrimeT x = and $ fmap ((/=0).(fstPow x (x-1))) $ take testn $ randomRs (2,(x-1)) (mkStdGen 100) + +fstPow _ 1 x = x +fstPow m y x + | y `mod` 2 == 1 = (x * (fstPow m (y `div` 2) (sqr x))) `mod` m + | otherwise = fstPow m (y `div` 2) (sqr x) + where sqr a = (a*a) `mod` m |