Data commit

Task/Miller-Rabin-primality-test/Julia/miller-rabin-primality-test.julia

@@ -0,0 +1,27 @@
+witnesses(n::Union(Uint8,Int8,Uint16,Int16)) = (2,3)
+witnesses(n::Union(Uint32,Int32)) = n < 1373653 ? (2,3) : (2,7,61)
+witnesses(n::Union(Uint64,Int64)) =
+        n < 1373653         ? (2,3) :
+        n < 4759123141      ? (2,7,61) :
+        n < 2152302898747   ? (2,3,5,7,11) :
+        n < 3474749660383   ? (2,3,5,7,11,13) :
+                              (2,325,9375,28178,450775,9780504,1795265022)
+
+function isprime(n::Integer)
+    n == 2 && return true
+    (n < 2) | iseven(n) && return false
+    s = trailing_zeros(n-1)
+    d = (n-1) >>> s
+    for a in witnesses(n)
+        a < n || break
+        x = powermod(a,d,n)
+        x == 1 && continue
+        t = s
+        while x != n-1
+            (t-=1) <= 0 && return false
+            x = oftype(n, Base.widemul(x,x) % n)
+            x == 1 && return false
+        end
+    end
+    return true
+end