Polynomial Class

[FrostyPine]

I wasn't given much information other than: develop a C++ class to describe and manipulate polynomials.

I tried but I messed up, and I have restarted several times but end up messing up more each time.

// Polynomial.h

#ifndef POLYNOMIAL_H
#define POLYNOMIAL_H

#include <iostream>
using std::ostream;
using std::istream;




class Polynomial
{

  public:
    Polynomial();
    Polynomial( int dgr, const double* clist );
    Polynomial( const Polynomial& );
    ~Polynomial();

    const Polynomial& operator=( const Polynomial& clist);
    bool operator==( const Polynomial& clist) const;


	int setDegree(int dgr); 
    int getDegree() const;

    void printPolynomial( int dgr, const double* clist );

	
     double operator[]( int index ) const;
    double& operator[]( int index );

  private:
	  int    degree;
	  double *coefficients; // list of coefficients

};

ostream& operator<<( ostream& , const Polynomial& );
istream& operator>>( istream& , Polynomial& );


#endif


// Polynomial.cpp

#include <iostream>
using std::cout;
using std::endl;
using std::cin;
using std::istream;
using std::ostream;
using std::cerr;
using std::endl;

#include <cstdlib>
using std::exit;

#include "Polynomial.h"


Polynomial::Polynomial()
{
	degree        = 0;
	coefficients  = 0;

}


Polynomial::Polynomial(int dgr, const double* clist)
{
	 getDegree();
	 
}

int Polynomial::getDegree() const
{
	return degree; 
}

Polynomial:: ~Polynomial()
{
	setDegree(0); 
}

int Polynomial::setDegree(int dgr)
{

	if( dgr <0 ) {
    cerr << "Error:  attempted to set a negative degree" << endl;
    exit(1);  
  } else {
    if( coefficients!=0 ) {
      delete [] coefficients;
      coefficients = 0;
      degree       = 0;
    }
    if( dgr !=0 ) {
      coefficients = new double [dgr];
      if( coefficients==0 ) {
        degree =0;
        cerr << "Warning:  unable to allocate enough space for list" << endl;
        exit(2); // this surely is reasonable.
      } else {
        degree=dgr;
      }
    }
  }
  return dgr;


}

//copy constructor 
Polynomial::Polynomial(const Polynomial& clist) : degree(0), coefficients(0)
{
  if( clist.getDegree()<=0 ) {
    setDegree(0);
  } else {
    setDegree(clist.getDegree());
    for (int i=0; i< degree ; i++) {
      coefficients[i]=clist.coefficients[i];
    }
  }
}


const Polynomial& Polynomial :: operator=(const Polynomial& clist) 
{
	if ( &clist==this ) 
	{
    cerr << "Warning:  attempt to copy Polynomial onto self" << endl;
    } 
	else {
    if( clist.getDegree()<=0 ) {
      setDegree(0);
    } else {
      setDegree(clist.getDegree());
      for (int i=0; i< degree ; i++) {
        coefficients[i] = clist.coefficients[i];
      }
    }
  }
  return *this;
}

bool  Polynomial::operator==(const Polynomial& clist) const
{
	bool result=true;
  if( degree!=clist.getDegree() ) {
    result=false;
  } else {
    for(int i=0; i< degree && result == true; i++) {
      result = coefficients[i]==clist.coefficients[i];
    }
  }
  return result;
}


double Polynomial::operator[]( int index ) const
{
  if( index<0 || index>= degree ) {
    cerr << "Attempt to access element outside index bounds" 
      << endl;
    exit(3); // Maybe not reasonable. 
  } else {
    return coefficients[index];
  }
}


double& Polynomial::operator[]( int index )
{
  if( index < 0 || index>= degree  ) {
    cerr << "Attempt to access element outside index bounds" 
      << endl;
    exit(4); // Maybe not reasonable but what the heck.
  } else {
    return coefficients[index];
  }
}






void printPolynomial( int dgr, const double* clist )
{   int beru;    

	for (int i = 0; i <= dgr ; i ++ ){
 


		
 
	cout << clist[i] << "X^(" << beru << ")" ;
	
		if (dgr != 0) {
		beru = dgr - 1;
		}
		else 
		{
		beru = dgr;  
		}
	

	if (beru > 0){
	
	cout << " + "; 
	} 

}

}

ostream& operator<<( ostream& left, const Polynomial& right)
{
  if( right.getDegree() > 0 ) {
    left << endl;
    for( int i=0; i< right.getDegree(); i++ ) {
      left << "[" << i << "] " << right[i] << endl;
    }
  } else {
    cerr << "Warning:  Attempt to display empty IntList" << endl;
  }
  return left;
}


istream& operator>>( istream& left, Polynomial& right)
{
  int tmp;
  left >> tmp;
  if( tmp<=0 ) {
    cerr << "First value expected to be list size, > 0." << endl;
  } else {
    if( tmp!=right.getDegree() ) {
      right.setDegree(tmp);
    }
    for (int i=0; i<right.getDegree(); i++) {
      left >> right[i];
    }
  }
  return left;
}

// Prog11.cpp

 
#include <iostream>
using std::cout;
using std::endl;
using std::cin;

#include "Polynomial.h"
#include "Polynomial.cpp"

int main()
{
  Polynomial A;
  cout << "(1) Testing `cout << A':  " << A << endl;

  cout << "(2) Testing `cin >> A':\n";
  cout << "Enter the polynomial (integer order then double coefficients):\n\t ";
  cin >> A;
  cout << endl;
  cout << "(3) Second look at A:  " << A << endl;

  Polynomial B(A);
  cout << "(4) Testing `Polynomial B(A)':  " << B << endl;

  double clist[]={8, 4.5, 1};
  Polynomial C(2, clist);
  cout << "(5) Testing `Polynomial C(2, clist)':  " << C << endl;

  Polynomial D=C;
  cout << "(6) Testing D = C):  " << D << endl;

  cout << "(7) Testing A == B :  " << (A==B ? "TRUE" : "FALSE") << endl;
  cout << "(8) Testing A == D :  " << (A==D ? "TRUE" : "FALSE") << endl;  

  return 0;
}

Example of what the basic out put should look like:
(1) Testing `cout << A': empty
(2) Testing `cin >> A':
Enter the polynomial (integer degree then double coefficients):
3 -1 2.09 -5.3 -0.98
(3) Second look at A: -1x^(3) +2.09x^(2) -5.3x^(1) -0.98
(4) Testing `Polynomial B(A)': -1x^(3) +2.09x^(2) -5.3x^(1) -0.98
(5) Testing `Polynomial C(2, clist)': +1x^(2) +4.5x^(1) +8
(6) Testing D = C: +1x^(2) +4.5x^(1) +8
(7) Testing A == B : TRUE
(8) Testing A == D : FALSE