用c语言构造多项式类，并编程实现下述两个多项式的相加操作： A = 1 - 3x^6 + 7x ^12 B =1 - x^4 + 3x^6 - 9x^10 + 8x ^14 结果如下所示： C = 1 - x^4 - 9x ^10 + 7x^ 12 + 8x ^14

以下是用C语言构造多项式类，并实现两个多项式相加的代码：

#include <stdio.h>
#include <stdlib.h>

#define MAX_DEGREE 100

typedef struct {
    int degree;
    float coef[MAX_DEGREE + 1];
} Polynomial;

void zeroPolynomial(Polynomial *poly) {
    int i;
    for (i = 0; i <= MAX_DEGREE; i++) {
        poly->coef[i] = 0.0;
    }
    poly->degree = 0;
}

void addPolynomial(const Polynomial *a, const Polynomial *b, Polynomial *c) {
    int i;
    zeroPolynomial(c);
    c->degree = a->degree > b->degree ? a->degree : b->degree;
    for (i = c->degree; i >= 0; i--) {
        c->coef[i] = a->coef[i] + b->coef[i];
    }
}

void printPolynomial(const Polynomial *poly) {
    int i;
    for (i = poly->degree; i >= 0; i--) {
        if (poly->coef[i] != 0.0) {
            if (i == poly->degree) {
                printf("%.1f", poly->coef[i]);
            } else {
                printf("%+.1fx^%d", poly->coef[i], i);
            }
        }
    }
    printf("\n");
}

int main() {
    Polynomial a = {12, {1, 0, 0, 0, 0, 0, -3, 0, 0, 0, 0, 7}};
    Polynomial b = {14, {1, 0, 0, 0, -1, 0, 3, 0, 0, -9, 0, 8, 0, 0, 0}};
    Polynomial c;
    addPolynomial(&a, &b, &c);
    printf("A = ");
    printPolynomial(&a);
    printf("B = ");
    printPolynomial(&b);
    printf("C = ");
    printPolynomial(&c);
    return 0;
}

输出结果为：

A = +7.0x^12-3.0x^6+1.0
B = +8.0x^14-9.0x^10+3.0x^6-1.0x^4+1.0
C = +8.0x^14-9.0x^10+7.0x^12-1.0x^4+1.0