addPoly.c

#include <stdio.h>
struct poly
{
    int coeff;
    int expo;
} p1[10], p2[10], p3[10];
int readPoly(struct poly[]);
int addPoly(struct poly[], struct poly[], int, int, struct poly[]);
void displayPoly(struct poly[], int term);
void main()
{
    int t1, t2, t3;
    t1 = readPoly(p1);
    printf("\nFirst polynomial: ");
    displayPoly(p1, t1);
    t2 = readPoly(p2);
    printf("\nSecond polynomial: ");
    displayPoly(p2, t2);

    t3 = addPoly(p1, p2, t1, t2, p3);
    printf("\n\nResultant polynomial after addition : ");
    displayPoly(p3, t3);
}
int readPoly(struct poly p[10])
{
    int n, i;
    printf("\nEnter the total number of terms in the polynomial : ");
    scanf("%d", &n);

    printf("\nEnter the coefficient and exponent in descending order\n");

    for (i = 0; i < n; i++)
    {
        printf("Enter the coeffcient(%d): ", i + 1);
        scanf("%d", &p[i].coeff);

        printf("Enter the exponent(%d): ", i + 1);
        scanf("%d", &p[i].expo);
    }

    return (n);
}
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);
}
int addPoly(struct poly p1[10], struct poly p2[10], int t1, int t2, struct poly p3[10])
{
    int 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;
            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++;
    }
    // k is the number of terms in resultant polynomial
    return (k);
}