program for addition of two polynomials

 /* program for addition of two polynomials

 * polynomial are stored using structure
 * and program uses array of structure
 */
#include<stdio.h>

/* declare structure for polynomial */
struct poly
{
int coeff;
int expo;
};
/* declare three arrays p1, p2, p3 of type structure poly.
 * each polynomial can have maximum of ten terms
 * addition result of p1 and p2 is stored in p3 */

struct poly p1[10],p2[10],p3[10];

/* function prototypes */
int readPoly(struct poly []);
int addPoly(struct poly [],struct poly [],int ,int ,struct poly []);
void displayPoly( struct poly [],int terms);

int main()
{
int t1,t2,t3;

/* read and display first polynomial */
t1=readPoly(p1);
printf(" \n First polynomial : ");
displayPoly(p1,t1);
/* read and display second polynomial */
t2=readPoly(p2);
printf(" \n Second polynomial : ");
displayPoly(p2,t2);

/* add two polynomials and display resultant polynomial */
t3=addPoly(p1,p2,t1,t2,p3);
printf(" \n\n Resultant polynomial after addition : ");
displayPoly(p3,t3);
printf("\n");

return 0;
}

int readPoly(struct poly p[10])
{
int t1,i;

printf("\n\n Enter the total number of terms in the polynomial:");
scanf("%d",&t1);

printf("\n Enter the COEFFICIENT and EXPONENT in DESCENDING ORDER\n");
for(i=0;i<t1;i++)
{
printf("   Enter the Coefficient(%d): ",i+1);
scanf("%d",&p[i].coeff);
printf("      Enter the exponent(%d): ",i+1);
scanf("%d",&p[i].expo);        /* only statement in loop */
}
return(t1);
}

int addPoly(struct poly p1[10],struct poly p2[10],int t1,int t2,struct poly p3[10])
{
int i,j,k;

i=0;
j=0;
k=0;

while(i<t1 && j<t2)
{
if(p1[i].expo==p2[j].expo)
{
p3[k].coeff=p1[i].coeff + p2[j].coeff;
p3[k].expo=p1[i].expo;

i++;
j++;
k++;
}
else if(p1[i].expo>p2[j].expo)
{
p3[k].coeff=p1[i].coeff;
p3[k].expo=p1[i].expo;
i++;
k++;
}
else
{
p3[k].coeff=p2[j].coeff;
p3[k].expo=p2[j].expo;
j++;
k++;
}
}

/* for rest over terms of polynomial 1 */
while(i<t1)
{
p3[k].coeff=p1[i].coeff;
p3[k].expo=p1[i].expo;
i++;
k++;
}
/* for rest over terms of polynomial 2 */
while(j<t2)
{
p3[k].coeff=p2[j].coeff;
p3[k].expo=p2[j].expo;
j++;
k++;
}

return(k); /* k is number of terms in resultant polynomial*/
}

void displayPoly(struct poly p[10],int term)
{
int k;

for(k=0;k<term-1;k++)
printf("%d(x^%d)+",p[k].coeff,p[k].expo);
printf("%d(x^%d)",p[term-1].coeff,p[term-1].expo);
}