gistfile1.txt

bool isPrime(int n) {
	//two is the only even prime
	if (n == 2) {
		return true;
	}
	//all less than two or divisable by two are not primes
	if (n < 2 || n % 2 == 0) {
		return false;
	}
	if(n%2==0){
		return false;
	}
	//starting from 3, and skipping evens, check up to floor(n/2) is not divisable by i
	for (int i = 3; i < n; i+=2) {
		if (n % i == 0) {
			return false;
		}
	}
	//finally
	return true;
}