C++ Poly::setCoeff方法代码示例

Poly* Poly::multiply(Poly* other)
{
   double TOL = .00001;

   int n = getDegree();
   int m = other->getDegree();

   Poly* temp = new Poly(n + m);

   for (int i = 0; i <= n; i++) //loop over coeffs
   {
      for (int j = 0; j <= m; j++)  //loop over second coeffs
      {
         double coeff_i = getCoeff(i);
         double coeff_j = other->getCoeff(j);
         if (fabs(coeff_i) > TOL && fabs(coeff_j) > TOL)
         {
            int power = i + j;
            double coeff = temp->getCoeff(power);
            temp->setCoeff(power, coeff + (coeff_i * coeff_j));
         }
      }
   }

   return temp;
}

Poly Poly::operator*(const Poly& p)
{
	int newTerms = this->terms + p.terms - 1;
	Poly output = Poly(0, newTerms - 1);

	int c, t;

	//iterate over the outside array
	for (int i = 0; i < this->terms; i++)
	{
		if (this->coeffs[i] == 0)
		{
			continue;
		}

		//iterate over the inside array
		for (int j = 0; j < p.terms; j++)
		{
			if (p.coeffs[j] == 0)
			{
				continue;
			}

			//get values
			c = this->coeffs[i] * p.coeffs[j];
			t = i + j;

			//assign values for new poly
			output.setCoeff(c, t);
		}
	}

	return output;
}

int main() {

	Poly count[8];

	cout << "Constructors" << endl;
	count[0] = Poly();
	count[1] = Poly(1);
	count[2] = Poly(0);
	count[3] = Poly(-1);
	count[4] = Poly(0, 1);
	count[5] = Poly(1, 1);
	count[6] = Poly(-1, 1);
	count[7] = Poly(1, -1);

	for (int i = 0; i < 8; i++) {
		cout << count[i] << endl;
	}

	cout << "add" << endl;
	count[0].setCoeff(2,2);
	count[0].setCoeff(4,4);
	count[0].setCoeff(3,3);
	count[2].setCoeff(2,2);
	count[2].setCoeff(4,4);
	count[2].setCoeff(3,3);

	cout << count[0] << endl;
	cout << count[2] << endl;

	Poly p = count[0] + count[2];

	cout << p << endl;

	p = p - count[0] - count[2];

	cout << p << endl;

	p = p - count[0];

	cout << p << endl;

	p.setCoeff(-1,-1);
	cout << p.getCoeff(-2) << endl;

	return 0;
}

//assumes a specific format for the file
//why is this method static in the header file?
Poly* Poly::readPoly(const char* file_name)
{
   ReadFile* rf = new ReadFile(file_name); //for reading
   String* degree_str = rf->readLine();
   int degree = degree_str->a_to_i();
   delete degree_str;

   Poly* poly = new Poly(degree);
   
   for (int i = 0; i <= degree; i++)
   {
      String* coeff_str = rf->readLine();
      float coeff = coeff_str->a_to_f();
      delete coeff_str;

      poly->setCoeff(i, (double) coeff);
   }

   delete rf;
   return poly;
}