프로젝트 오일러 문제 7

10001st prime

Problem 7

By listing the first six prime numbers: 2, 3, 5, 7, 11, and 13, we can see that the 6th prime is 13.

What is the 10 001st prime number?

10,001번째 소수가 무엇인지를 구하는 문제

long long int Problem007(unsigned int number)
{
	long long int ret;
	unsigned int count = 0;
	for (int i = 2; true; i++)
	{
		if (IsPrime(i))
		{
			ret = i; 
			count++;
		}
		if (count == number)
		{
			break;
		}
	}
	return ret;
}
bool IsPrime(int number)
{
	bool ret = true;
	for (int i = 2; i * i <= number; i++)
	{
		if (number % i == 0)
		{
			ret = false;
			break;
		}
	}
	return ret;
}