Polynomial multiplication program using data structures in c?

Answer 1

#include <stdio.h>

#include <conio.h>

#define MAX 10

struct term

{

int coeff ;

int exp ;

} ;

struct poly

{

struct term t [10] ;

int noofterms ;

} ;

void initpoly ( struct poly *) ;

void polyappend ( struct poly *, int, int ) ;

struct poly polyadd ( struct poly, struct poly ) ;

struct poly polymul ( struct poly, struct poly ) ;

void display ( struct poly ) ;

void main( )

{

struct poly p1, p2, p3 ;

clrscr( ) ;

initpoly ( &p1 ) ;

initpoly ( &p2 ) ;

initpoly ( &p3 ) ;

polyappend ( &p1, 1, 4 ) ;

polyappend ( &p1, 2, 3 ) ;

polyappend ( &p1, 2, 2 ) ;

polyappend ( &p1, 2, 1 ) ;

polyappend ( &p2, 2, 3 ) ;

polyappend ( &p2, 3, 2 ) ;

polyappend ( &p2, 4, 1 ) ;

p3 = polymul ( p1, p2 ) ;

printf ( "\nFirst polynomial:\n" ) ;

display ( p1 ) ;

printf ( "\n\nSecond polynomial:\n" ) ;

display ( p2 ) ;

printf ( "\n\nResultant polynomial:\n" ) ;

display ( p3 ) ;

getch( ) ;

}

/* initializes elements of struct poly */

void initpoly ( struct poly *p )

{

int i ;

p -> noofterms = 0 ;

for ( i = 0 ; i < MAX ; i++ )

{

p -> t[i].coeff = 0 ;

p -> t[i].exp = 0 ;

}

}

/* adds the term of polynomial to the array t */

void polyappend ( struct poly *p, int c, int e )

{

p -> t[p -> noofterms].coeff = c ;

p -> t[p -> noofterms].exp = e ;

( p -> noofterms ) ++ ;

}

/* displays the polynomial equation */

void display ( struct poly p )

{

int flag = 0, i ;

for ( i = 0 ; i < p.noofterms ; i++ )

{

if ( p.t[i].exp != 0 )

printf ( "%d x^%d + ", p.t[i].coeff, p.t[i].exp ) ;

else

{

printf ( "%d", p.t[i].coeff ) ;

flag = 1 ;

}

}

if ( !flag )

printf ( "\b\b " ) ;

}

/* adds two polynomials p1 and p2 */

struct poly polyadd ( struct poly p1, struct poly p2 )

{

int i, j, c ;

struct poly p3 ;

initpoly ( &p3 ) ;

if ( p1.noofterms > p2.noofterms )

c = p1.noofterms ;

else

c = p2.noofterms ;

for ( i = 0, j = 0 ; i <= c ; p3.noofterms++ )

{

if ( p1.t[i].coeff p2.t[j].exp )

{

p3.t[p3.noofterms].coeff = p1.t[i].coeff + p2.t[j].coeff ;

p3.t[p3.noofterms].exp = p1.t[i].exp ;

i++ ;

j++ ;

}

else

{

p3.t[p3.noofterms].coeff = p1.t[i].coeff ;

p3.t[p3.noofterms].exp = p1.t[i].exp ;

i++ ;

}

}

else

{

p3.t[p3.noofterms].coeff = p2.t[j].coeff ;

p3.t[p3.noofterms].exp = p2.t[j].exp ;

j++ ;

}

}

return p3 ;

}

/* multiplies two polynomials p1 and p2 */

struct poly polymul ( struct poly p1, struct poly p2 )

{

int coeff, exp ;

struct poly temp, p3 ;

initpoly ( &temp ) ;

initpoly ( &p3 ) ;

if ( p1.noofterms != 0 && p2.noofterms != 0 )

{

int i ;

for ( i = 0 ; i < p1.noofterms ; i++ )

{

int j ;

struct poly p ;

initpoly ( &p ) ;

for ( j = 0 ; j < p2.noofterms ; j++ )

{

coeff = p1.t[i].coeff * p2.t[j].coeff ;

exp = p1.t[i].exp + p2.t[j].exp ;

polyappend ( &p, coeff, exp ) ;

}

if ( i != 0 )

{

p3 = polyadd ( temp, p ) ;

temp = p3 ;

}

else

temp = p ;

}

}

return p3 ;

}