public static bool IsPrime(this Int64 number)
{
if (number < 2)
{
return(false);
}
else if (number < 4)
{
return(true);
}
var limit = (Int32)System.Math.Sqrt(number) + 1;
var foundPrimes = new PrimesInt32(limit);
return(!foundPrimes.IsDivisible(number));
}
public static bool IsPrime(this Int64 number)
{
if (number < 2)
{
return(false);
}
else if (number < 4)
{
return(true);
}
if (primes != null && primes.IsDivisible(number))
{
return(false);
}
var limit = (Int32)System.Math.Sqrt(number);
var foundPrimes = new PrimesInt32(limit);
if (foundPrimes.Count() > primes.Count())
{
primes = foundPrimes;
}
return(!foundPrimes.IsDivisible(number));
}
static PrimeHelper()
{
primes = new PrimesInt32(10000000);
}
