//Prime test is in p for O:log6(N)
private static bool IsPrimeByAgrawalKayalSaxena(
BigInteger n)
{
BigInteger X = 0;
BigInteger r = 0;
BigInteger a = 0;
BigInteger b = 0;
if (a.Pow(b) == n)
{
return(false);
}
//TODO Find the smallest r such that Or(n) > (log2 n) 2.
for (a = r; a > 1; a--)
{
BigInteger gcd = ToolsMathBigInteger.GetGCDByModulus(a, n);
if (1 < gcd && gcd < n)
{
return(false);
}
}
if (n <= r)
{
return(true);
}
BigInteger upper_bound = ToolsMath.Sqrt(EulerPhi(r)) * 1;
for (a = 0; a < upper_bound; a++)
{
if ((X + a).Pow(n) != X.Pow(n) + a * (X.Pow(r) - 1) % n)
{
return(false);
}
}
return(true);
}
public static bool IsReverseTruncatablePrime(
BigInteger current)
{
if (!IsPrime(current))
{
return(false);
}
while (1 < current.ToString().Length)
{
current = ToolsMathBigInteger.ReverseDigits(current);
current = BigInteger.Parse(current.ToString().Substring(1));
current = ToolsMathBigInteger.ReverseDigits(current);
if (!IsPrime(current))
{
return(false);
}
}
return(true);
}