Micro optimization on trial division

WrathfulSpatula · WrathfulSpatula · commit a0987c567a06 · 2025-01-11T22:13:21.000-05:00
diff --git a/FindAFactor/_find_a_factor.cpp b/FindAFactor/_find_a_factor.cpp
@@ -837,8 +837,13 @@ struct Factorizer {
       }
       num /= factor;
       for (size_t pi = 0U; pi < primes.size(); ++pi) {
-        if (!(factor % primes[pi])) {
+        const BigInteger& p = primes[pi];
+        if (!(factor % p)) {
+          factor /= p;
           vec[pi] = !vec[pi];
+          if (factor == 1U) {
+            break;
+          }
         }
       }
       if (num == 1U) {
diff --git a/setup.py b/setup.py
@@ -26,7 +26,7 @@
 
 setup(
     name='FindAFactor',
-    version='3.6.2',
+    version='3.6.3',
     author='Dan Strano',
     author_email='dan@unitary.fund',
     description='Find any nontrivial factor of a number',

Original file line number	Diff line number	Diff line change
`@@ -837,8 +837,13 @@ struct Factorizer {`
`837`	`837`	`}`
`838`	`838`	`num /= factor;`
`839`	`839`	`for (size_t pi = 0U; pi < primes.size(); ++pi) {`
`840`		`- if (!(factor % primes[pi])) {`
	`840`	`+ const BigInteger& p = primes[pi];`
	`841`	`+ if (!(factor % p)) {`
	`842`	`+ factor /= p;`
`841`	`843`	`vec[pi] = !vec[pi];`
	`844`	`+ if (factor == 1U) {`
	`845`	`+ break;`
	`846`	`+ }`
`842`	`847`	`}`
`843`	`848`	`}`
`844`	`849`	`if (num == 1U) {`