# HG changeset patch
# User Eris Caffee <discordia@eldalin.com>
# Date 1433365351 18000
# Node ID 8f82abf1b732d3a6e9547d95ff55f349881d4273
# Parent  707cbc379d260e2d2ac2dc7ee14a306e55909925
Sieve of Eratosthenes in C++

diff -r 707cbc379d26 -r 8f82abf1b732 sieve_of_eratosthenes/sieve.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sieve_of_eratosthenes/sieve.cpp	Wed Jun 03 16:02:31 2015 -0500
@@ -0,0 +1,42 @@
+#include <iostream>
+#include <vector>
+#include <cmath>
+#include <sstream>
+
+void sieve( int limit, std::vector<int> &primes ) {
+    std::vector<int> nums;
+    for ( int i = 0; i <= limit; ++i )
+        nums.push_back(1);
+    nums[0] = nums[1] = 0;
+
+
+    float sq = sqrt(limit);
+    for ( int i = 2; i <= sq; ++i ) {
+        if ( nums[i] != 0 ) {
+            for ( int j = i*i; j <= limit; j += i )
+                nums[j] = 0;
+            }
+        }
+
+    for ( int i = 2; i <= limit; ++i )
+        if ( nums[i] != 0 )
+            primes.push_back( i );
+
+    }
+
+
+
+int main( int argc, char **argv ) {
+    int limit;
+
+    std::stringstream ss(argv[1]);
+    ss >> limit;
+
+    std::vector<int> primes;
+
+    sieve( limit, primes );
+
+    for ( int i=0; i < primes.size(); ++i )
+        std::cout << primes[i] << std::endl;
+
+    }