Write a program to multiply two polynomials using an array?

Answer 1

#include<stdio.h>

#include<malloc.h>

int* getpoly(int);

void showpoly(int *,int);

int* addpoly(int *,int,int *,int);

int* mulpoly(int *,int,int *,int);

int main(void)

{

int *p1,*p2,*p3,d1,d2,d3;

/*get poly*/

printf("\nEnter the degree of the 1st polynomial:");

scanf("%d",&d1);

p1=getpoly(d1);

printf("\nEnter the degree of the 2nd polynomial:");

scanf("%d",&d2);

p2=getpoly(d2);

printf("Polynomials entered are\n\n");

showpoly(p1,d1);

printf("and\n\n");

showpoly(p2,d2);

/*compute the sum*/

d3=(d1>=d2?d1:d2);

p3=addpoly(p1,d1,p2,d2);

printf("Sum of the polynomials is:\n");

showpoly(p3,d3);

/*compute product*/

p3=mulpoly(p1,d1,p2,d2);

printf("Product of the polynomials is:\n");

showpoly(p3,d1+d2);

}

int* getpoly(int degree)

{

int i,*p;

p=malloc((1+degree)*sizeof(int));

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

{

printf("\nEnter coefficient of x^%d:",i);

scanf("%d",(p+i));

}

return(p);

}

void showpoly(int *p,int degree)

{

int i;

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

printf("%dx^%d + ",*(p+i),i);

printf("\b\b\b ");

printf("\n");

}

int* addpoly(int *p1,int d1,int *p2,int d2)

{

int i,degree,*p;

degree=(d1>=d2?d1:d2);

p=malloc((1+degree)*sizeof(int));

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

if((i>d1) && (i<=d2))

*(p+i)=*(p2+i);

else if((i>d2) && (i<=d1))

*(p+i)=*(p1+i);

else

*(p+i)=*(p1+i)+*(p2+i);

return(p);

}

int* mulpoly(int *p1,int d1,int*p2,int d2)/* this is the function of concern*/

{

int i,j,*p;

p=malloc((1+d1+d2)*sizeof(int));

for(i=0;i<=d1;i++)

for(j=0;j<=d2;j++)

p[i+j]+=p1[i]*p2[j];

return(p);

}