Write a program to add two polynomials using a linked list

#include

#include

#include

struct poly_node

{

            int coeff, expo;

            struct poly_node *link;

};

typedef struct poly_node poly;

poly *insert_polynode(int, int, poly*);

class polynode

{

            public:

                        poly *insert_polynode(int coeff, int expo, poly *polynomial);

                        poly *create_polynomial();

                        void display_polynomial(poly *p);

                        poly *add_polynomial(poly *poly1, poly *poly2);

};

poly *polynode::insert_polynode(int coeff, int expo, poly *polynomial)

{

            poly *newnode, *currptr, *prevnode;

            newnode = new poly;

            newnode->coeff = coeff;

            newnode->expo = expo;

            newnode->link = NULL;

            if (!polynomial)

            {

                        return newnode;

            }

            prevnode = polynomial;

            for (currptr=polynomial ;currptr ;currptr=currptr->link )

            {

                        prevnode = (poly*)currptr;

            }

            prevnode->link = newnode;

            return polynomial;

}

poly *polynode::create_polynomial()

{

            int coeff, expo;

            poly *polynomial = NULL;

            while (1)

            {

                        cout <<  "\nEnter coefficient and exponent :\t" ;

                        cin >> coeff >> expo;

                        if (coeff==0)

                        {

                                    continue;

                        }

                        polynomial = insert_polynode(coeff, expo, polynomial);

                        if (expo==0)

                        {

                                    break;

                        }

            }

            return polynomial;

}

void polynode::display_polynomial(poly *p)

{

            poly *currptr;

            for (currptr=p ;currptr ;currptr=currptr->link )

            {

                        if (currptr->expo==0)

                        {

                                    cout << currptr->coeff;

                        }

                        else if (currptr->coeff!=0)

                        {

                                    cout <coeff << "X^" << currptr->expo << " + " ;

                        }

            }

}

poly *polynode::add_polynomial(poly *poly1, poly *poly2)

{

            poly *p1, *p2, *result=NULL;

            p1 = poly1;

            p2 = poly2;

            while (p1&&p2)

            {

                        if (p1->expo>p2->expo)

                        {

                                    result = insert_polynode(p1->coeff, p1->expo,result);

                                    p1 = p1->link;

                        }

                        else if (p1->expoexpo)

                        {

                                    result = insert_polynode(p2->coeff, p2->expo, result);

                                    p2 = p2->link;

                        }

                        else

                        {

                                    result = insert_polynode(p1->coeff+p2->coeff, p1->expo, result);

                                    p1 = p1->link;

                                    p2 = p2->link;

                        }

            }

            while (p1)

            {

                        result = insert_polynode(p1->coeff, p1->expo, result);

                        p1->link = p1;

            }

            while (p2)

            {

                        result = insert_polynode(p2->coeff, p2->expo, result);

                        p2->link = p2;

            }

            return result;

}

void main()

{

            polynode obj;

            poly *poly1 = NULL, *poly2 = NULL, *poly3 = NULL;

            clrscr();

            cout << "\nEnter First polynomial\n" ;

            poly1 = obj.create_polynomial();

            cout << "\n\n" ;

            obj.display_polynomial(poly1);

            cout << "\n\nEnter Second polynomial\n" ;

            poly2 = obj.create_polynomial();

            cout << "\n\n" ;

            obj.display_polynomial(poly2);

            cout << "\n\nAddition of two polynomials\n" ;

            poly3 = obj.add_polynomial(poly1, poly2);

            cout << "\n\n" ;

            obj.display_polynomial(poly3);

            getch();

}