polynomial.cpp

#include <iostream>
#include <cmath>
using namespace std;

class Polynomial {
	double a,b,c;
public:
	Polynomial() {} //Default constructor
	Polynomial(const Polynomial& poly_old); //Copy constructor
	Polynomial(double a, double b, double c) {
		this->a = a;
		this->b = b;
		this->c = c;
	}
	Polynomial operator+(const Polynomial& poly);
	Polynomial operator-(const Polynomial& poly);
	void operator++(int);
	void operator--(int);
	bool operator==(const Polynomial& poly);
	void showpoly();
	void roots();

	//Getters
	double getA() const {return a;}
	double getB() const {return b;}
	double getC() const {return c;}

	//Setters
	void setA(double val) {a = val;}
	void setB(double val) {b = val;}
	void setC(double val) {c = val;}
	
	~Polynomial() {} //Default destructor
	
};

Polynomial::Polynomial(const Polynomial& poly_old) {
	a = poly_old.getA();
	b = poly_old.getB();
	c = poly_old.getC();
}

Polynomial Polynomial::operator+(const Polynomial& poly) {
	Polynomial tmp;
	tmp.setA(a + poly.getA());
	tmp.setB(b + poly.getB());
	tmp.setC(c + poly.getC());
	return tmp;
}

Polynomial Polynomial::operator-(const Polynomial& poly) {
	Polynomial tmp;
	tmp.setA(a - poly.getA());
	tmp.setB(b - poly.getB());
	tmp.setC(c - poly.getC());
	return tmp;
}

void Polynomial::operator++(int) {
	a++; b++; c++;
}

void Polynomial::operator--(int) {
	a--; b--; c--;
}

bool Polynomial::operator==(const Polynomial& poly) {
	return (poly.getA() == a) && (poly.getB() == b) && (poly.getC() == c);
}

void Polynomial::showpoly() {
	char bb, bc;
	//Set the operators
	bb = (b < 0) ? '-' : '+';
	bc = (c < 0) ? '-' : '+';

	//Print out the polynomials
	if (a == 0) {
		cout << b << "x " << bc << " " << abs(c) << "\n";
		if (b == 0) cout << c << "\n";
	} else if (b == 0) {
		cout << a << "x^2 " << bc << " " << abs(c) << "\n";
	}
	else cout << a << "x^2 " << bb << " " << abs(b) << "x " << bc << " " << abs(c) << "\n";
}

void Polynomial::roots() {
	double x1, x2;
	x1 = (-b + sqrt(b*b - 4*a*c)) / 2*a;
	x2 = (-b - sqrt(b*b - 4*a*c)) / 2*a;
	
	//Prints out -nan for complex roots
	if (x1 == x2) {
		cout << x1 << "\n";
	} else {
		cout << x1 << " " << x2 << "\n";
	}
}

int main() {
	//Testing the class
	Polynomial f(1, -2, -3);
	Polynomial g(1, 5, 7);
	f.showpoly();
	f.roots();
	Polynomial f_copy = f;
	Polynomial y(1, 1, 1);
	Polynomial z = f + y;
	f_copy.showpoly();
	z.showpoly();
	cout << (f_copy == f) << "\n";
	cout << (f == z) << "\n";
	g++;
	g.showpoly();
	return 0;
}