A tutorial for the shipyard testing library.

primelib.cpp

#include <cmath>
#include <vector>

bool is_prime(const uint32_t n)
{
	if ((n & 1) == 0 && n != 2)
		return false;
	for (uint32_t i = 3; i < std::sqrt(n) + 1; i += 2)
		if (n % i == 0)
			return false;
	return true;
}

uint32_t n_prime(const uint32_t n)
{
	if (n == 1)
		return 2;

	uint32_t to_test = 3, prime_count = 1;

	while (prime_count <= n) {
		if (is_prime(to_test)) {
			prime_count++;
			if (prime_count == n)
				return to_test;
		}
		to_test += 2;
	}
	return to_test;
}

std::vector<uint32_t> primes_till(const uint32_t n)
{
	uint32_t to_test = 3;
	std::vector<uint32_t> primes = {2};
	while (primes.size() != n) {
		if (is_prime(to_test))
			primes.push_back(to_test);
		to_test += 2;
	}
	return primes;
}