EratosthenesAlgorithmPrimeNumbers

using System;
using System.Collections.Generic;

class EratosthenesAlgorithmPrimeNumbers
{
    static void Main()
    {
        DateTime a1 = DateTime.Now;
        // Define the Array
        int length = 10000000;
        bool[] array = new bool[length];
        List<long> arrayPrime = new List<long>();

        for (int i = 0; i < array.Length; i++)
        {
            array[i] = true;
        }

        // Get the prime numbers "Eratosthenes Algorithm"
        long j = 0;
        for (long i = 2; i < array.Length; i++)
        {
            if (array[i] == true)
            {
                arrayPrime.Add(i);
                j = i * i;
            }
            while (j < array.Length)
            {
                array[j] = false;
                j = j + i;
            }
        }

        // Print
        for (int i = 0; i < arrayPrime.Count - 100; i++)
        {
            Console.Write(arrayPrime[i] + " ");
        }
        Console.WriteLine();
        DateTime a2 = DateTime.Now;
        Console.WriteLine(a2 - a1);
    }
}