( enpassant | 2013. 03. 21., cs – 09:15 )

Nehogy részrehajlással vádoljatok, legyen itt a C# mono verzió is (0,93x):

using System;

public class Prime {
    public static int COUNT = 10000000;

    public static void Main(string[] args) {
        int[] primeArr = new int[COUNT];
        int count = 0;
        for (int i = 2; i<=COUNT; i++) {
            int k = (int) Math.Sqrt(i);
            bool isPrime = true;
            for (int j = 2; j <= k; j++) {
                if (i % j == 0) {
                    isPrime = false;
                    break;
                }
            }
            if (isPrime) {
                primeArr[count] = i;
                count += 1;
            }
        }

        Console.WriteLine(count);
    }
}

gmcs prime.cs
time mono prime.exe