public void Multiply(Natural factor1, Natural factor2, out Natural product)
{
if (factor1 == Natural.Zero || factor2 == Natural.Zero)
{
product = Natural.Zero;
}
else if (factor1 == Natural.One)
{
product = factor2.Clone();
}
else
{
Natural counter = factor2.Clone();
product = factor1.Clone();
product.PushLength(factor1.usedDigits * factor2.usedDigits);
while (counter > 1) // We already have 1 factor1
{
Natural.Add(product, factor1);
Natural.Decrement(counter);
}
product.PopLength();
}
}
public void Multiply(Natural factor1, Natural factor2, out Natural product)
{
if (factor1 == 0 || factor2 == 0)
{
product = Natural.Zero;
}
else if (factor2 == 1)
{
product = factor1.Clone();
}
else
{
product = Natural.Zero;
for (int i = 0; i < factor1.usedDigits; i++)
{
Digit d = factor1.digits[i];
Natural partial = MulDigit(factor2, d);
Natural.ShiftLeft(partial, i);
Natural.Add(product, partial);
}
}
}
public void Multiply(Natural factor1, Natural factor2)
{
if (factor1 == Natural.Zero || factor2 == Natural.Zero)
{
factor1.SetValue(Natural.Zero);
}
else if (factor1 == Natural.One)
{
factor1.SetValue(factor2);
}
else
{
Natural increase = factor1.Clone();
Natural decrease = factor2.Clone();
factor1.PushLength(factor1.usedDigits * factor2.usedDigits);
while (decrease > 1) // We already have 1 factor1
{
Natural.Add(factor1, increase);
Natural.Decrement(decrease);
}
factor1.PopLength();
}
}
static bool LucasLehmerTest(ulong exponent, Natural mersenneNumber, ref ulong startI, ref Natural startS)//3815
{
Natural s = startS.Clone();
for (ulong i = startI; i < exponent; s = ModMersenneNumber2(Square(s), (int)exponent), i++)
{
;
}
if (startS < mersenneNumber)
{
startI++;
startS *= startS;
}
return(s == mersenneNumber - 3);
}
public void DivRem(Natural dividend, Natural divisor, out Natural quotient, out Natural remainder)
{
if (divisor == 0)
throw new DivideByZeroException();
dividend = dividend.Clone();
quotient = 0;
while (dividend >= divisor)
{
Natural.Subtract(dividend, divisor);
Natural.Increment(quotient);
}
remainder = dividend;
}
private void InternalDivRem(Natural dividend, Natural divisor, out Natural quotient, out Natural remainder)
{
int dcmp = dividend.CompareTo(divisor);
if (dcmp == 0)
{
quotient = Natural.One;
remainder = Natural.Zero;
}
else if (dcmp < 0) // dividend < divisor
{
quotient = Natural.Zero;
remainder = dividend.Clone(); // Do we have to clone?
}
else // dividend > divisor
{
Natural modifiedDivisor = divisor.Clone();
Natural subquotient = Natural.One;
long bitshifts = Natural.Log2(dividend) - Natural.Log2(modifiedDivisor); // Gets how many factors of two from divisor to dividend
Natural.BitShiftLeft(modifiedDivisor, bitshifts); // Shifts divisor that many times (multiply by 2^bitshifts)
Natural.BitShiftLeft(subquotient, bitshifts);
int cmp = dividend.CompareTo(modifiedDivisor);
if (cmp < 0) // Dividend < modifiedDivisors - shifted 1 too much
{
Natural.BitShiftRight(subquotient, 1); // Divide by 2 to get the right quotient
Natural.BitShiftRight(modifiedDivisor, 1);
}
else if (cmp == 0) // Divisor equal to dividend!
{
quotient = subquotient;
remainder = Natural.Zero;
return;
}
// dividend > modifiedDivisor
Natural newDividend = Natural.Subtract(dividend, modifiedDivisor); // Optimize away the clone (put this in private function - clone up front)
InternalDivRem(newDividend, divisor, out quotient, out remainder); // Repeat division on difference between dividend and modifiedDivisor
Natural.Add(quotient, subquotient); // Add the quotient we calculated in this iteration
}
}
public void Subtract(Natural minuend, Natural subtrahend, out Natural difference)
{
difference = minuend.Clone();
Subtract(difference, subtrahend);
}
public void DivRem(Natural dividend, Natural divisor, out Natural quotient, out Natural remainder)
{
InternalDivRem(dividend.Clone(), divisor, out quotient, out remainder);
}
public void Add(Natural addend1, Natural addend2, out Natural sum)
{
sum = addend1.Clone();
Add(sum, addend2);
}
public Integer(Natural natural)
{
this.natural = natural.Clone();
Positive = true;
}
public Natural Abs() => natural.Clone();