From 2a535141fbe0c06424283f8a01a7e2c8a1180ed7 Mon Sep 17 00:00:00 2001
From: Reiner Herrmann <reiner@reiner-h.de>
Date: Fri, 20 Nov 2009 01:26:36 +0100
Subject: further optimization on problem 10 :)

---
 src/projecteuler/010.py | 21 +++++++++++++++++----
 1 file changed, 17 insertions(+), 4 deletions(-)

diff --git a/src/projecteuler/010.py b/src/projecteuler/010.py
index 475ade8..691c7a5 100644
--- a/src/projecteuler/010.py
+++ b/src/projecteuler/010.py
@@ -1,14 +1,27 @@
-import math
-
 limit = 2000000
 
 number_list = [False] + [True]*(limit-1)
+list_len = len(number_list)
+
+def next_prime(i):
+	global number_list
+	global list_len
+	x = i+1
+	while(x <= list_len):
+		if number_list[x-1] == True:
+			break
+		x += 1
+	return x
 
-for i in xrange(2, int(math.sqrt(limit+1))):
+i = 2
+
+while(i*i <= list_len):
 	x = i*i
-	while(x <= len(number_list)):
+	while(x <= list_len):
 		number_list[x-1] = False
 		x += i
+	i = next_prime(i)
+
 
 sum = 0
 
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