I am supposed to implement an ADT polynomial, using an array for polynomial coefficients- using-

degree() - gives the highest degree in the polynomial.

coefficient(power)throw(InvalidPowerException)

changeCoefficient(newCoefficient, power)throw(InvalidPowerException)

overloaded + operator to add 2 polynomials

overloaded << operator

I cannot use a list class for this project.

special cout cases:

+1, -1 coefficients: don't display the 1 (unless power is 0)

power 0: don't display x^0

negative coefficients: don't display +

dirst term: don't display a preceding +

I am going to paste everything I did- the problem is when I am trying to slowly create the private data member (string) finalStr, it will not do the proper +, and I don't have a string to show at the end. it has got to be in the makeFinalString function.

```
#include <iostream>
#include <string>
using namespace std;
class Polynomial
{
private:
int thing[10];
string finalStr;
public:
void makeFinalString(Polynomial& poly);
Polynomial(const Polynomial& poly); // copy constructor
Polynomial(); //default constructor
~Polynomial(); // Destructor
void setPolynomial();
void showPolynomial();
friend Polynomial operator+(const Polynomial& poly_a, const Polynomial& poly_b);
friend ostream& operator<<(ostream& out, const Polynomial& poly);
};
//#endif
Polynomial::Polynomial()
{
for(int i=0; i<10; i++)//initialize to 0's
thing[i]=0;
for(int i =0;i<10;i++)//display the polynomial
cout << thing[i] << " ";
cout << endl << "default constructor called\n";
}
Polynomial::~Polynomial()
{
cout << "Destructor called\n";
}
void Polynomial::setPolynomial()
{
int coefficient = 0;
int power = 0;
cout << "Please input values for the polynomial:\n";
while(cin >> coefficient >> power)
{
if(power<0)
break; // throw
if(coefficient<0 && power<0)
break; //end of polynomial
if(power>9)
break; //throw
if(thing[power]==0)
thing[power] = coefficient;
else
thing[power] +=coefficient;
}
for(int i =0;i<10;i++)//display the polynomial
cout << thing[i] << " ";
}
void Polynomial::showPolynomial()
{
bool success = 0;
for(int i=9;i>=0;i--)
{
if(i == 0 && thing[0]!=0) // if power is 0
{
if(thing[0]<0)
{
cout << thing[0];
}
else
{
if(success==1)
cout << "+" << thing[0];
else
cout << thing[0];
}
}
if(i == 1 && thing[1]!=0) //if power is 1
{
if(thing[1]<0)
{
cout << thing[1] << "x";
success = 1;
}
else //if(thing[1]>0)
{
if(success ==1)
{
cout << "+" << thing[1] << "x";
}
else
{
cout << thing[1] << "x";
success = 1;
}
}
}
if(i>1 && thing[i]!=0) //if power is greater than 1
{
if(thing[i]<0)
{
cout << thing[i] << "x^" << i;
success = 1;
}
else //if(thing[i]>0)
{
if(success==1)
{
cout << "+" << thing[i] <<"x^" << i;
}
else
{
cout << thing[i] << "x^" << i;
success = 1;
}
}
}
}
}
Polynomial::Polynomial(const Polynomial& poly)
{
for(int i=0; i<10; i++)
thing[i] = poly.thing[i];
finalStr = poly.finalStr;//??? or do I just want to re-calculate it?
cout << "Copy constructor called\n";
}
Polynomial operator+(const Polynomial& polyA, const Polynomial& polyB)
{
Polynomial tempPoly;
for(int i=0; i<10; i++)
{
tempPoly.thing[i] = polyA.thing[i]+polyB.thing[i];
}
return tempPoly;//or do I want to recalculate the finalStr???
}
ostream& operator<<(ostream& out, const Polynomial& poly)
{
out << poly.finalStr;
return out;
}
void Polynomial::makeFinalString(Polynomial& poly)
{
bool success = 0;
for(int i=9;i>=0;i--)
{
if(i == 0 && poly.thing[0]!=0) // if power is 0
{
if(poly.thing[0]<0)
{
poly.finalStr += poly.thing[0];
cout << endl << poly.finalStr;
}
else
{
if(success==1)
{
poly.finalStr += '+';
poly.finalStr += poly.thing[0];
cout << endl << poly.finalStr;
}
else
poly.finalStr += poly.thing[0];
cout << endl << poly.finalStr;
}
}
if(i == 1 && poly.thing[1]!=0) //if power is 1
{
if(poly.thing[1]<0)
{
poly.finalStr += poly.thing[1]; + 'x';
success = 1;
cout << endl << poly.finalStr;
}
else //if(thing[1]>0)
{
if(success ==1)
{
poly.finalStr += '+' + poly.thing[1] + 'x';
cout << endl << poly.finalStr;
}
else
{
poly.finalStr += poly.thing[1] + 'x';
success = 1;
cout << endl << poly.finalStr;
}
}
}
if(i>1 && poly.thing[i]!=0) //if power is greater than 1
{
if(poly.thing[i]<0)//if coefficient is smaller than zero
{
if(poly.thing[i]!=1 && poly.thing[i]!=-1)//and it is not -1 or 1
{
poly.finalStr += poly.thing[i] + 'x^' + i;
success = 1;
cout << endl << poly.finalStr;
}
else//it is smaller than zero and it is -1 or 1
{
if(poly.thing[i]==-1)//if it is -1
{
poly.finalStr += '-x^' + i;
success = 1;
cout << endl << poly.finalStr;
}
else//it must be 1
{
poly.finalStr += 'x^' + i;
success = 1;
cout << endl << poly.finalStr;
}
}
}
else //if(thing[i]>0)
{
if(success==1)//it is not the first number
{
poly.finalStr += '+' + poly.thing[i] + 'x^' + i;
cout << endl << poly.finalStr;
}
else//it is the first number
{
poly.finalStr += poly.thing[i] + 'x^' + i;
success = 1;
cout << endl << poly.finalStr;
}
}
}
}
cout << endl << poly.finalStr << endl;
}
int main()
{
Polynomial x;
x.setPolynomial();
cout << endl;
x.makeFinalString(x);
cout << x;
cout << endl;
}
```

PLEASE HELP!!!!

I need to create a polynomial adder function at the end.