if is_prime(n): return n

Author: daedalus

pollard_rho.py

@@ -0,0 +1,24 @@
+from gmpy2 import isqrt, gcd, is_prime
+import sys
+
+def pollard_rho(self, n, seed=2, p=2, mode=1):
+        if is_prime(n):
+            return n
+        if n % 2 == 0:
+            return 2
+        if n % 3 == 0:
+            return 3
+        if n % 5 == 0:
+            return 5
+        if mode == 1:
+            f = lambda x: x ** p + 1
+        else:
+            f = lambda x: x ** p - 1
+        x, y, d = seed, seed, 1
+        while d == 1:
+            x = f(x) % n
+            y = f(f(y)) % n
+            d = gcd((x - y) % n, n)
+        return None if d == n else d
+        
+print(int(sys.argv[1]))