Hello, I'm having trouble with multiple parts in my polynomial program. First of all, I can't seem to find a way to access the mySize variable from the Polynomial class, also, I'm not quite sure how to combine the liketerms, and finally if you could give me some tips for the multiplication function in Polynomial class. Any help would be appreciated.

polynomial.cpp
Code:
#include <cassert>
using namespace std;

#include "Polynomial.h"


/*----------------------------------------------------------------------
 Member and friend functions for Monomial.
 -----------------------------------------------------------------------*/

Monomial operator+(Monomial& a, Monomial& b) {

	Monomial res;

	for(int i = 0; i < mySize; i++){ // Attempting to access mySize from here and combine liketerms
		if(a.exp == b.exp){
			res.coef = a.coef + b.coef;
			res.exp = a.exp;
		}
		else if(a.exp != b.exp){
			res.coef = a.coef;
			res.exp = a.exp;
		}
		else if(b.exp != a.exp){
			res.coef = b.coef;
			res.exp = b.exp;
		}
	}

return res;

}

Monomial operator-(Monomial& a, Monomial& b) {
    Monomial res;

    for(int i = 0; i < mySize; i++){ // Attempting to access mySize from here and combine liketerms
		if(a.exp == b.exp){
			res.coef = a.coef - b.coef;
			res.exp = a.exp;
		}
		else if(a.exp != b.exp){
			res.coef = a.coef;
			res.exp = a.exp;
		}
		else if(b.exp != a.exp){
			res.coef = b.coef;
			res.exp = b.exp;
		}
    }
return res;

}

Monomial operator*(Monomial& a, Monomial& b) {
    Monomial res;

    res.coef = a.coef * b.coef;
    res.exp  = a.exp + b.exp;

    return res;
}


ostream & operator<< (ostream & out, const Monomial & mono)
{
	out << mono.coef ;
	if (mono.exp > 0) out << "x^" << mono.exp; 
	return out;
}


/*----------------------------------------------------------------------
 Member and friend functions for Polinomial.
 -----------------------------------------------------------------------*/

Polynomial::Polynomial()                 
: mySize(0)
{}


bool Polynomial::empty() const
{
   return mySize == 0;
}


void Polynomial::display(ostream & out) const
{
	for (int i = mySize-1; i >= 0 ; i--) {
		if (i != mySize-1) out << " + ";
		out << myArray[i];
	}

}


ostream & operator<< (ostream & out, const Polynomial & aList)
{
   aList.display(out);
   return out;
}


void Polynomial::insert(ElementType item, int pos)
{
   if (mySize == CAPACITY)
   {
      cerr << "*** No space for list element -- terminating "
              "execution ***\n";
      exit(1);
   }
   if (pos < 0 || pos > mySize)
   {
      cerr << "*** Illegal location to insert -- " << pos 
           << ".  List unchanged. ***\n";
      return;
   }

   // First shift array elements right to make room for item

   for(int i = mySize; i > pos; i--)
      myArray[i] = myArray[i - 1];

   // Now insert item at position pos and increase list size  
   myArray[pos] = item;
   mySize++;
}


void Polynomial::erase(int pos)
{
   if (mySize == 0)
   {
      cerr << "*** List is empty ***\n";
      return;
   }
   if (pos < 0 || pos >= mySize)
   {
      cerr << "Illegal location to delete -- " << pos
           << ".  List unchanged. ***\n";
      return;
   }

   // Shift array elements left to close the gap
   for(int i = pos; i < mySize; i++)
       myArray[i] = myArray[i + 1];

   // Decrease list size
    mySize--;
}

Polynomial operator+(Polynomial &p1, Polynomial &p2){
    Polynomial res;
    int i = 0;

    if (p1.mySize > p2.mySize){
        res.mySize = p1.mySize;
    }else{
        res.mySize = p2.mySize;
    }

    for(i = 0; i < res.mySize; i++){
        res.myArray[i] = p1.myArray[i] + p2.myArray[i];
    }

return res;

}

Polynomial operator*(Polynomial &p1, Polynomial &p2){ // Multiplication does not work properly
    Polynomial res;
    int i = 0;

    if (p1.mySize > p2.mySize){
        res.mySize = p1.mySize;
    }
	else{
        res.mySize = p2.mySize;
    }

    /*for(i = 0; i < res.mySize; i++){
        res.myArray[i] = p1.myArray[i] * p2.myArray[i];
    }*/
	
	for (i = 0; i < res.mySize; i++){
		for (int j=0; j < res.mySize; j++){
			res.myArray[i+j] = (p1.myArray[i]*p2.myArray[j]) ;
		 }
	}
return res;

}
polynomial.h
Code:
#include <iostream>

#ifndef PNOM
#define PNOM

const int CAPACITY = 1024;


class Monomial {
protected:
	int coef;
	int exp;
	// int size;
public:
	Monomial(){};
	/*----------------------------------------------------------------------
	 Construct a Monomial object.
	 
	 Precondition:  None
	 Postcondition: An empty Monomial object has been constructed..
   -----------------------------------------------------------------------*/
	Monomial(int c,int p) { coef = c; exp = p;};

	friend Monomial operator+ (Monomial&, Monomial&);

	friend Monomial operator- (Monomial&, Monomial&);

	friend Monomial operator* (Monomial&, Monomial&);

	friend class Polynomial;

	int getExponent() {return exp;}
	
    int getCoefficient() {return coef;}
    
	/*----------------------------------------------------------------------
	 Construct a Monomial object with specified coeffient and exponent.
	 
	 Precondition:  None
	 Postcondition: A Monomial object has been constructed with the 
                  specified coeffient and exponent.
   -----------------------------------------------------------------------*/

	friend ostream & operator<< (ostream & out, const Monomial & mono);	
	/*----------------------------------------------------------------------
	 Overloading the OUTPUT operator for Monomials. 
	 
	 Precondition:  None.
	 Postcondition: The coefficient and exponent (if != 0) of the monomial are 
	                displayed in the default output device.
   -----------------------------------------------------------------------*/
};

typedef Monomial ElementType;

class Polynomial
{
 public:

	friend class Monomial;

   Polynomial();
   /*----------------------------------------------------------------------
     Construct a List object.

     Precondition:  None
     Postcondition: An empty List object has been constructed; mySize is 0.
   -----------------------------------------------------------------------*/

   /***** empty operation *****/
   bool empty() const;
   /*----------------------------------------------------------------------
     Check if a list is empty.

     Precondition:  None
     Postcondition: true is returned if the list is empty, false if not.
   -----------------------------------------------------------------------*/

   /***** insert and erase *****/
   void insert(ElementType item, int pos);
   /*----------------------------------------------------------------------
     Insert a value into the list at a given position.

     Precondition:  item is the value to be inserted; there is room in
         the array (mySize < CAPACITY); and the position satisfies
         0 <= pos <= mySize. 
     Postcondition: item has been inserted into the list at the position
         determined by pos (provided there is room and pos is a legal
         position).
   -----------------------------------------------------------------------*/

   void erase(int pos);
   /*----------------------------------------------------------------------
     Remove a value from the list at a given position.

     Precondition:  The list is not empty and the position satisfies
         0 <= pos < mySize.
     Postcondition: element at the position determined by pos has been
         removed (provided pos is a legal position).
   ----------------------------------------------------------------------*/ 

	friend Polynomial operator+(Polynomial &, Polynomial &);

	friend Polynomial operator*(Polynomial &, Polynomial &);

   /***** output *****/
   void display(ostream & out) const;

 protected:
   int mySize;                     // current size of list stored in myArray
   ElementType myArray[CAPACITY];  // array to store the Monomials

}; //--- end of List class

//------ Prototype of output operator
ostream & operator<< (ostream & out, const Polynomial & p);

#endif