chore: import upstream snapshot with attribution

math/prime_numbers.cpp

@@ -0,0 +1,41 @@
+/**
+ * @file
+ * @brief Get list of prime numbers
+ * @see primes_up_to_billion.cpp sieve_of_eratosthenes.cpp
+ */
+#include <iostream>
+#include <vector>
+
+/** Generate an increasingly large number of primes
+ * and store in a list
+ */
+std::vector<int> primes(size_t max) {
+    std::vector<int> res;
+    std::vector<bool> is_not_prime(max + 1, false);
+    for (size_t i = 2; i <= max; i++) {
+        if (!is_not_prime[i]) {
+            res.emplace_back(i);
+        }
+        for (int p : res) {
+            size_t k = i * p;
+            if (k > max) {
+                break;
+            }
+            is_not_prime[k] = true;
+            if (i % p == 0) {
+                break;
+            }
+        }
+    }
+    return res;
+}
+
+/** main function */
+int main() {
+    std::cout << "Calculate primes up to:\n>> ";
+    int n = 0;
+    std::cin >> n;
+    std::vector<int> ans = primes(n);
+    for (int p : ans) std::cout << p << ' ';
+    std::cout << std::endl;
+}