public double ResilenceFactorFast(ulong n)
{
PrimeCalculator calc = new PrimeCalculator();
var factors = calc.Factor(n).Distinct().ToList();
ulong count = (ulong)factors.Count;
long cancelNum = (long)n-1;
for (ulong i = 1; i < (ulong)Math.Pow(2,count); i++)
{
ulong tmp = i;
int index = 0;
ulong bitNum = 0;
long mul = -1;
while (tmp > 0)
{
if (tmp % 2 == 1)
mul *= -factors[index];
tmp /= 2;
index++;
}
long numDiv = (long)(n-1) / mul;
cancelNum -= numDiv;
}
var factor = (double)cancelNum / (n - 1);
return factor;
}
static ulong Calculate(ulong n)
{
PrimeCalculator calculator = new PrimeCalculator();
var primes = calculator.GetAllPrimes_Atkin(n);
ulong maxPrime = primes[primes.Count - 1];
ulong sum = 0;
for (int i = 0; i < primes.Count - 2; i++)
{
if (i%10000==0)
Console.WriteLine(i);
var a = primes[i];
var factors = (ulong)calculator.Factor(a + 1).Distinct().Prod();
if (factors > 10)
{
sum += CalculateByFactor(a, factors, maxPrime, primes);
}
else
{
sum += CalculateByPrimes(i, primes, a, maxPrime);
}
}
return sum;
}
static void CalculateRads(int n)
{
var primeCalculator = new PrimeCalculator();
_rads = new int[n+1];
_rads[1] = 1;
for (int i = 2; i <= n; i++)
{
_rads[i] = primeCalculator.Factor(i).Distinct().Prod();
}
}
public int Calculate(int n, int k)
{
PrimeCalculator calculator = new PrimeCalculator();
var primes = calculator.GetAllPrimes(n);
var primeCounts = new Dictionary<int, int>();
for (int i=n-k+1; i<=n; i++)
{
if (i%10000==0)
Console.WriteLine(i);
var factors = calculator.Factor(i);
foreach (int factor in factors)
{
if (primeCounts.ContainsKey(factor))
primeCounts[factor] = primeCounts[factor] + 1;
else
{
primeCounts.Add(factor, 1);
}
}
}
for (int i = 2; i <= k; i++)
{
var factors = calculator.Factor(i);
foreach (int factor in factors)
{
primeCounts[factor] = primeCounts[factor] - 1;
}
}
int sum = 0;
foreach (var primeCount in primeCounts)
{
sum += primeCount.Key * primeCount.Value;
}
return sum;
}
static ulong NumOfDivisorSquare(ulong n, PrimeCalculator calc)
{
var primes = calc.Factor(n);
return (ulong)primes.GroupBy(x => x).Select(x => x.Count()*2 + 1).Prod();
//return Tuple.Create(primes.GroupBy(x => x).Select(x => x.Count() + 1).Prod(), primes.Count());
}
static void Main(string[] args)
{
PrimeCalculator calculator = new PrimeCalculator();
//Console.WriteLine(calculator.Factor(600851475143).Last().ToString());
Console.WriteLine(calculator.Factor(600851475143).Last().ToString());
}