public static PolynomialOverFiniteField Rem(PolynomialOverFiniteField firstArg, PolynomialOverFiniteField secondArg)
{
var field = secondArg._field;
var firstDeg = firstArg.Deg;
var secondDeg = secondArg.Deg;
var newDeg = firstDeg - secondDeg;
var result = new Polynomial[newDeg + 1];
var reminder = (Polynomial[])firstArg._coefficients.Clone();
var mod = secondArg._mod;
Polynomial firstLc;
Polynomial secondLc = secondArg[secondDeg];
for (int i = 0; i <= newDeg; i++)
{
firstLc = reminder[firstDeg - i];
result[newDeg - i] = field.Div(firstLc, secondLc);
for (int j = 0; j <= secondDeg; j++)
{
if (reminder[firstDeg - secondDeg + j - i] != null)
{
reminder[firstDeg - secondDeg + j - i] = field.Add
(reminder[firstDeg - secondDeg + j - i], (field.Mul(result[newDeg - i], secondArg[j])));
}
else
{
reminder[firstDeg - secondDeg + j - i] = (field.Mul(result[newDeg - i], secondArg[j]));
}
}
}
return(new PolynomialOverFiniteField(reminder, field));
}
public static PolynomialOverFiniteField Mul(PolynomialOverFiniteField firstArg, PolynomialOverFiniteField secondArg)
{
int firstDeg = firstArg._deg;
int secondDeg = secondArg._deg;
var field = secondArg._field;
if (firstDeg == -1 || secondDeg == -1)
{
return(new PolynomialOverFiniteField(new Polynomial[] { Polynomial.Zero }, secondArg._field));
}
int maxdegree = firstDeg + secondDeg;
Polynomial[] result = new Polynomial[maxdegree + 1];
for (int i = 0; i <= firstDeg; i++)
{
for (int j = 0; j <= secondDeg; j++)
{
if (result[i + j] != null)
{
result[i + j] = field.Add(result[i + j], (field.Mul(firstArg[i], secondArg[j])));
}
else
{
result[i + j] = (field.Mul(firstArg[i], secondArg[j]));
}
}
}
return(new PolynomialOverFiniteField(result, field));
}
public static PolynomialOverFiniteField Sub(PolynomialOverFiniteField firstArg, PolynomialOverFiniteField secondArg)
{
int firstDeg = firstArg._deg;
int secondDeg = secondArg._deg;
var field = secondArg._field;
var maxDeg = Math.Max(firstDeg, secondDeg);
if (maxDeg == -1)
{
return(new PolynomialOverFiniteField(new Polynomial[] { Polynomial.Zero }, field));
}
var result = new Polynomial[maxDeg + 1];
if (firstDeg > secondDeg)
{
int i;
for (i = 0; i <= secondDeg; i++)
{
result[i] = field.Sub(firstArg[i], secondArg[i]);
}
for (; i <= firstDeg; i++)
{
result[i] = firstArg[i];
}
}
else
{
int i;
for (i = 0; i <= firstDeg; i++)
{
result[i] = field.Sub(firstArg[i], secondArg[i]);
}
for (; i <= secondDeg; i++)
{
result[i] = field.Sub(Polynomial.Zero, secondArg[i]);
}
}
return(new PolynomialOverFiniteField(result, field));
}
