From a021ec6ea3633a6604c535ca76d704477d075e16 Mon Sep 17 00:00:00 2001
From: cdkr <775481991@qq.com>
Date: Sat, 21 Jun 2014 03:10:26 +0800
Subject: [PATCH] Optimized test_prime

---
 include/prime.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/prime.h b/include/prime.h
index 8780dfd3..fd7b73ef 100644
--- a/include/prime.h
+++ b/include/prime.h
@@ -35,7 +35,7 @@ namespace alg {
 		if (n%2	== 0) return false;
 
 		unsigned sqrtn = sqrt(n);
-		for (unsigned int i = 2; i <= sqrtn; ++i) {
+		for (unsigned int i = 3; i <= sqrtn; i+=2) {
 			if (n % i == 0) {
 				return false;
 			}