/// <summary>
/// Finds all the prime numbers up to maxNumber.
/// If the number is larger than n, an out of memory exception will be thrown, based on the current available memory.
/// </summary>
/// <param name="maxNumber"></param>
/// <returns></returns>
private List <long> SieveOfEratostenes(int maxNumber)
{
Int64[] result = new Int64[maxNumber + 1];
HashSet <Int64> nonPrimes = new HashSet <Int64>();
for (Int64 i = 2; i < maxNumber + 1; i++)
{
result[i - 2] = i;
}
for (Int64 i = 0; i < result.Length; i++)
{
int p = 2;
if (!nonPrimes.Contains(result[i]))
{
while (p <= maxNumber)
{
Int64 x = result[i] * p;
p++;
if (x <= maxNumber && !nonPrimes.Contains(x))
{
nonPrimes.Add(x);
}
}
}
}
var finalResult = result.Except(nonPrimes);
Console.WriteLine();
foreach (int elem in finalResult)
{
Console.Write(elem + ", ");
}
Console.ReadLine();
return(finalResult.ToList());
}