Question # prime number theory

• Prime number theorem: For a number of prime numbers positive real number x, x is smaller than the slightly greater than x / lnx
• Goldbach conjecture: positive even number greater than or equal 6 each may be decomposed into two prime numbers and
• 0 and 1 are neither prime nor composite

Prime decision

bool prime(int x)
{
	if(x == 0 || x == 1)	return false;
	if((x%2 == 0) && (x != 2))	return false;
	for(int i=3;i<=sqrt(x);i+=2)
	{
		if(x % i == 0)
			return false;
	}
	return true;
}

Prime 筛法