internal ModulusPoly multiply(ModulusPoly other)
{
if (!field.Equals(other.field))
{
throw new ArgumentException("ModulusPolys do not have same ModulusGF field");
}
if (isZero || other.isZero)
{
return(field.getZero());
}
int[] aCoefficients = this.coefficients;
int aLength = aCoefficients.Length;
int[] bCoefficients = other.coefficients;
int bLength = bCoefficients.Length;
int[] product = new int[aLength + bLength - 1];
for (int i = 0; i < aLength; i++)
{
int aCoeff = aCoefficients[i];
for (int j = 0; j < bLength; j++)
{
product[i + j] = field.add(product[i + j], field.multiply(aCoeff, bCoefficients[j]));
}
}
return(new ModulusPoly(field, product));
}
public ModulusPoly(ModulusGF field, int[] coefficients)
{
if (coefficients.Length == 0)
{
throw new ArgumentException();
}
this.field = field;
int coefficientsLength = coefficients.Length;
if (coefficientsLength > 1 && coefficients[0] == 0)
{
// Leading term must be non-zero for anything except the constant polynomial "0"
int firstNonZero = 1;
while (firstNonZero < coefficientsLength && coefficients[firstNonZero] == 0)
{
firstNonZero++;
}
if (firstNonZero == coefficientsLength)
{
this.coefficients = field.getZero().coefficients;
}
else
{
this.coefficients = new int[coefficientsLength - firstNonZero];
Array.Copy(coefficients,
firstNonZero,
this.coefficients,
0,
this.coefficients.Length);
}
}
else
{
this.coefficients = coefficients;
}
}
public ModulusPoly(ModulusGF field, int[] coefficients)
{
if (coefficients.Length == 0)
{
throw new ArgumentException();
}
this.field = field;
int coefficientsLength = coefficients.Length;
if (coefficientsLength > 1 && coefficients[0] == 0)
{
// Leading term must be non-zero for anything except the constant polynomial "0"
int firstNonZero = 1;
while (firstNonZero < coefficientsLength && coefficients[firstNonZero] == 0)
{
firstNonZero++;
}
if (firstNonZero == coefficientsLength)
{
this.coefficients = field.getZero().coefficients;
}
else
{
this.coefficients = new int[coefficientsLength - firstNonZero];
Array.Copy(coefficients,
firstNonZero,
this.coefficients,
0,
this.coefficients.Length);
}
}
else
{
this.coefficients = coefficients;
}
}