#ifndef POLYNOMIAL_H
#define POLYNOMIAL_H

#include <vector>
#include <string>

using namespace std;

//The Polynomial class represents a polynomial equation.
//Author: Robert Russell
//Date: April 11, 2009
class Polynomial
{
public:
	//Constructor: Creates an instance of Polynomial. This instance
	//of Polynomial does not contain an equation.
	Polynomial();

	//Constructor: Creates an instance of Polynomial.
	//In: A string containing the polynomial equation.
	//Out: None
	Polynomial(string equation);

	//Evaluates the polynomial based on the given value for the variable.
	//In: The value of the variable for the polynomail.
	//Out: The value of the polynomial. 
	double eval(int variable);

	//Returns the vector containing information about the polynomial equation.
	//In: None
	//Out: The vector containing information about the polynomial equation.
	vector<pair<double, int> >getPolynomial();

	//Adds two polynomial equations together.
	//In: The given polynomial to add with this polynomial.
	//Out: A new instance of Polynomial that is the result of
	//adding both instances of Polynomial.
	Polynomial operator+(Polynomial &secondPolynomial);

        //Takes the difference of two polynomial equations.
        //In: The given polynomial to subtract from this polynomial.
        //Out: A new instance of Polynomial that is the result of
        //taking the difference of both instances of Polynomial.
	Polynomial operator-(Polynomial &secondPolynomial);

        //Multiply two polynomial equations together.
        //In: The given polynomial to multiply with this polynomial.
        //Out: A new instance of Polynomial that is the result of
        //multiplying both instances of Polynomial.
	Polynomial operator*(Polynomial &secondPolynomial);

	//Determine whether the given polynomial is equal to this Polynomial.
	//In: The given instance of Polynomial.
	//Out: True if both instances of Polynomial are equal, false otherwise.
	bool operator==(Polynomial &secondPolynomial);

        //Determine whether the given polynomial is unequal to this Polynomial.
        //In: The given instance of Polynomial.
        //Out: True if both instances of Polynomial are unequal, false otherwise.
	bool operator!=(Polynomial &secondPolynomial);

	friend ostream &operator<<(ostream &stream, Polynomial &polynomial);
	friend istream &operator>>(istream &stream, Polynomial &polynomial);

private:
	//Constructor: Creates an instance of Polynomial.
	//In: A vector of pairs representing the polynomial equation.
	//Out: None
	Polynomial(vector<pair<double, int> > polynomial);

	//Vector of pairs representing the polynomial.
	vector<pair<double, int> > polynomial;
};

#endif // POLYNOMIAL_H