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?
class Program
{
private static List<long> primes = new List<long>(10000000);
static void Main(string[] args)
{
primes.Add(2);
for (int i = 0; primes.Count < 10001; i++)
{
NextPrime();
}
Console.WriteLine(primes.Last());
}
private static long NextPrime()
{
long last = primes.Last();
long n = last + 1;
while (true)
{
foreach (var item in primes)
{
if (n % item == 0)
{
goto LoopOut;
}
}
primes.Add(n);
return n;
LoopOut:
n++;
}
}
}