From a9abc1da41b56edbed00081800382e854d6698d0 Mon Sep 17 00:00:00 2001 From: Joe Zhao <ztuowen@gmail.com> Date: Tue, 31 Mar 2015 23:41:55 +0800 Subject: rename to H**, +31 +32 +33 +34 +35 +36 --- H31.hs | 15 +++++++++++++++ 1 file changed, 15 insertions(+) create mode 100644 H31.hs (limited to 'H31.hs') diff --git a/H31.hs b/H31.hs new file mode 100644 index 0000000..9c321ca --- /dev/null +++ b/H31.hs @@ -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 -- cgit v1.2.3-70-g09d2