public Polynomial[] Divide(Polynomial polynomial)
{
var newLength = coefficients.Length;
var quotient = new Polynomial(new int[newLength]);
var dividend = this;
var divisorGreatestPower = polynomial.GreatestPower();
var dividendGreatestPower = dividend.GreatestPower();
//only divide if divisable
while (dividendGreatestPower >= divisorGreatestPower)
{
var powerNeeded = dividendGreatestPower - divisorGreatestPower;
var coefficientNeeded = dividend.coefficients[dividendGreatestPower] / polynomial.coefficients[divisorGreatestPower];
//correct sign
coefficientNeeded = dividend.coefficients[dividendGreatestPower] > 0 ? Math.Abs(coefficientNeeded) : -1 * Math.Abs(coefficientNeeded);
//build new polynomial
var quotientCoefficient = new int[newLength];
quotientCoefficient[powerNeeded] = coefficientNeeded;
var partialQuotient = new Polynomial(quotientCoefficient);
//add onto the quotient
quotient = quotient.Sum(partialQuotient);
//multiply new quotient into divisor and subtract from current
//dividend for new dividend
dividend = dividend.Difference(polynomial.Product(partialQuotient));
//calculate top power of new dividend.
dividendGreatestPower = dividend.GreatestPower();
}
return(new Polynomial[] { quotient, dividend });
}