C Program for addition of polynomial

Program

//Addition of polynomial using array
#include<stdio.h>
void main()
{

int a[5],b[5],c[10],d1,d2,d;
void read_poly(int [],int);
void display_poly(int [], int);
void add_poly(int [],int,int [],int,int []);


printf("\nEnter degree of first polynomial: ");
scanf("%d",&d1);
read_poly(a,d1);
display_poly(a,d1);

printf("\nEnter degree of second polynomial: ");
scanf("%d",&d2);
read_poly(b,d2);
display_poly(b,d2);

if(d1>d2)
d=d1;
else
d=d2;

add_poly(a,d1,b,d2,c);
display_poly(c,d);
getch();
}

void read_poly(int poly[5],int degree)
{
int i;
printf("\nEnter first polynomial\n");
for(i=degree;i>0;i--)
{
printf("X^%d : ",i);
scanf("%d",&poly[i]);
}
printf("\nEnter constant term of first polynomial : ");
scanf("%d",&poly[0]);
}

void display_poly(int poly[10],int degree)
{
int i;
for(i=degree;i>0;i--)
printf("%dX^%d+",poly[i],i);
printf("%d\n",poly[0]);
}

void add_poly(int poly1[5], int degree1, int poly2[5], int degree2,int poly3[10])
{
int i,j,k;
k=1;
if(degree1>=degree2)
{
for(i=1;i<=degree2;i++)
{
poly3[k++]=poly1[i]+poly2[i];
}
for(j=i;j<=degree1;j++)
{
poly3[k++]=poly1[j];
}
poly3[0]=poly1[0]+poly2[0];
}

if(degree2>degree1)
{
for(i=0;i<=degree1;i++)
{
poly3[k++]=poly1[i]+poly2[i];
}
for(j=i;j<=degree2;j++)
{
poly3[k++]=poly1[j];
}
poly3[0]=poly1[0]+poly2[0];

}
}