public long SmallestNumberDividedByAllNumbers(long UpToNumber)
{
long[] maxCountOfPrimNumber = new long[UpToNumber + 1];
for (int i = 2; i <= UpToNumber; i++)
{
var group = Primes.GetPrimeFactorsInNumber(i).GroupBy(e => e);
foreach (var g in group)
{
if (maxCountOfPrimNumber[g.Key] < g.Count())
{
maxCountOfPrimNumber[g.Key] = g.Count();
}
}
}
long smallestNumber = 1;
for (int i = 2; i <= UpToNumber; i++)
{
for (int ii = 0; ii < maxCountOfPrimNumber[i]; ii++)
{
smallestNumber *= i;
}
}
return(smallestNumber);
}
private static List <int> ConvertToPrimeList(List <int> nrliste)
{
if (nrliste.Count() > 0)
{
List <long> liste = new List <long>();
foreach (int item in nrliste)
{
liste.AddRange(Primes.GetPrimeFactorsInNumber(item));
}
nrliste = liste.Select(e => (int)e).ToList();
}
return(nrliste);
}
public int GetNumberWithOneIntegerRightTriangles(int maxLengde)
{
Dictionary <long, long> lenDict = new Dictionary <long, long>();
for (int n = 1; n < 1000; n++)
{
List <long> nPrimes = Primes.GetPrimeFactorsInNumber(primeFactors, primeDict, n);
for (int m = n + 1; m < 1000; m++)
{
//en og kun skal være par..
if ((m + n) % 2 == 0)
{
continue;
}
//m og n skal være coprime
List <long> mPrimes = Primes.GetPrimeFactorsInNumber(primeFactors, primeDict, m);
if (nPrimes.Any(np => m % np == 0))
{
continue;
}
//Pythagorean triangles :https://en.wikipedia.org/wiki/Integer_triangle
int a = m * m - n * n;
int b = 2 * m * n;
int c = m * m + n * n;
int lengde = a + b + c;
int step = lengde;
while (lengde <= maxLengde)
{
if (lenDict.ContainsKey(lengde))
{
lenDict[lengde] = lenDict[lengde] + 1;
}
else
{
lenDict.Add(lengde, 1);
}
// hvis a,b,c er løsning , er også 2a,2b,2c løsing ,osv...
lengde += step;
}
} // for m
} // for n
//finn antall med bare en løsning/lengde
return(lenDict.Where(e => e.Value == 1).Count());
}
//hvis Numerator har felles primetall med denominator, kan brøken reduseres..
private int GetNoneReducableInInterval(long numeratorStart, long numeratorEnd, int denominator)
{
int counter = 0;
List <long> PrimeFactorsInDenominator = Primes.GetPrimeFactorsInNumber(denominator).ToList();
for (long numerator = numeratorStart; numerator <= numeratorEnd; numerator++)
{
if (!PrimeFactorsInDenominator.Any(p => numerator % p == 0))
{
counter++;
}
}
return(counter);
}
public long Largest(long below)
{
return(Primes.GetPrimeFactorsInNumber(below).Max());
}
public void TestPrimeIsNotPrimet(long value)
{
List <long> list = Primes.GetPrimeFactorsInNumber(value);
Assert.False(Primes.IsPrime(value));
}
public void TestPrimeList(long value, int len)
{
List <long> list = Primes.GetPrimeFactorsInNumber(value);
Assert.Equal(len, list.Count);
}
