sieve: iteration 1

cpp/sieve/sieve.cpp

@@ -0,0 +1,29 @@
+#include "sieve.h"
+
+namespace sieve {
+
+using namespace std;
+
+primes_t primes(size_t n)
+{
+    primes_t result;
+
+    vector<char> sieve(n, false);
+
+    for (size_t p = 2; p < n; ++p) {
+
+        if (sieve[p])
+            continue;
+
+        result.push_back(p);
+
+        for (size_t i = p*p; i < n; i += p) {
+
+            sieve[i] = true;
+        }
+    }
+
+    return result;
+}
+
+}