overloading operator *

[aaronmk2]

I am multiplying two polynomials and cannot figure out how to add the exponents. The loop is to multiply the coefficients and degree is for the total degrees used in the polynomial. But I can't figure out what I should use to add the exponents.

Poly Poly:: operator*(const Poly& p)
{
	
	Poly temp;//declare to hold new result
	for (int i=0; i<degree+1; i++){
		temp.coefs[i] =coefs[i] * p.coefs[i];
	}
		temp.degree = degree;
	return temp;
}

Here is the entire code

#include <iostream>
using namespace std;
#ifndef _POLY_H
#define _POLY_H
const int CAPACITY =100;
 
 
class Poly {
public:
	Poly();
	~Poly();
	void display(ostream & out)const;
	void input(istream &in);
	int evaluate(int x);
	Poly operator+(const Poly &p);
	Poly operator *(const Poly &p);
private:
	int degree;
	int coefs[CAPACITY];
};
ostream & operator<<(ostream & out, const Poly & p);
istream & operator>>(istream &in, Poly &p);
#endif
 
 
 
#include "Poly.h"
#include <iostream>
#include <cmath>
using namespace std;
 
Poly::Poly():degree(0){
	for (int i=0; i<CAPACITY; i++) {
		coefs[i]=NULL;
	}
}
Poly::~Poly(){
}
void Poly::display(ostream &out)const{
	for (int i=0; i<degree; i++) {
		out<<coefs[i]<<"x^"<<i<<" + ";
	}
	for (int i=degree; i<degree+1; i++) {
		out<<coefs[i]<<"x^"<<i;
	}
 
}
void Poly::input(istream & in){
	in>>degree;
	for (int i=0; i<degree+1; i++) {
		in>>coefs[i];
	}
}
int Poly::evaluate(int x){
	int sum=0;
	double xd = static_cast<double>(x);
	double totalPow;
	for (int i=0; i<degree+1; i++) {
		totalPow =pow(xd, i);
		sum+=(coefs[i]*totalPow);
	}
	return sum;
 
}
Poly Poly:: operator+(const Poly& p)
{
	Poly temp;//declare to hold new result
	if (degree < p.degree) {
		degree=p.degree;
	}
	for (int i=0; i<degree+1; i++){
	temp.coefs[i] =coefs[i] + p.coefs[i];
	}
	temp.degree = degree;
	return temp;
 
}
Poly Poly:: operator*(const Poly& p)
{
 
	Poly temp;//declare to hold new result
	for (int i=0; i<degree+1; i++){
		temp.coefs[i] =coefs[i] * p.coefs[i];//I don't know what to do here to add the exponents of the coefficients.  This is also where I get zero after the shorter polynomial ends.
	}
		temp.degree = degree;
	return temp;
}
istream & operator>>(istream & in, Poly &p){
	p.input(in);
	return in;
}
ostream &operator<<(ostream &out, const Poly &p){
	p.display(out);
	return out;
}
 
#include <iostream>
#include "Poly.h"
using namespace std;
 
int main () {
	Poly p1, p2, p3, p4;
	int x;
    cout << "Please enter the number of degrees you want followed by the number of coefficints: ";
	cin>>p1;
	cout<<endl;
	cout << "Please do the same again: ";
	cin>>p2;
	cout << "P1 = "<<p1<<endl;
	cout << "What do you want x to be for P1: ";
	cin>>x;
	cout << "P1 ="<<p1.evaluate(x)<<endl;
	cout <<" P2 = "<<p2<<endl;
	p3=p1+p2;
	cout << "addition "<<p3<<endl;
	p4=p1 *p2;
	cout << "time "<<p4<<endl;
    return 0;
}