Data commit

Task/Miller-Rabin-primality-test/Ring/miller-rabin-primality-test.ring

@@ -0,0 +1,48 @@
+# Project : Miller–Rabin primality test
+
+see "Input a number: " give n
+see "Input test: " give k
+
+test =  millerrabin(n,k)
+if test = 0
+   see "Probably Prime" + nl
+else
+   see "Composite" + nl
+ok
+
+func millerrabin(n, k)
+       if n = 2
+          millerRabin = 0
+          return millerRabin
+       ok
+       if n % 2 = 0 or n < 2
+          millerRabin = 1
+          return millerRabin
+       ok
+       d = n - 1
+       s = 0
+       while d % 2 = 0
+               d = d / 2
+               s = s + 1
+       end
+       while k > 0
+               k = k - 1
+               base = 2 + floor((random(10)/10)*(n-3))
+               x = pow(base, d) % n
+               if x != 1 and x != n-1
+                  for r=1 to s-1
+                      x = (x * x) % n
+                      if x = 1
+                         millerRabin = 1
+                         return millerRabin
+                      ok
+                      if x = n-1
+                         exit
+                      ok
+                  next
+                  if x != n-1
+                     millerRabin = 1
+                     return millerRabin
+                  ok
+                ok
+     end