c语言编写一个程序实现两个一元多项式相乘

下面给出一个C语言程序实现两个一元多项式相乘的功能：

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

#define MAXSIZE 100

typedef struct {
    float coef; // 系数
    int expn; // 指数
} ElemType, PolyNode;

typedef struct {
    PolyNode data[MAXSIZE];
    int length;
} PolyList;

void CreatePoly(PolyList *L) {
    printf("请输入多项式的项数：");
    scanf("%d", &L->length);
    printf("请按指数递减的顺序输入各项系数：\n");
    for (int i = 0; i < L->length; i++) {
        scanf("%f%d", &L->data[i].coef, &L->data[i].expn);
    }
}

void PrintPoly(PolyList L) {
    printf("多项式为：");
    for (int i = 0; i < L.length; i++) {
        if (i == 0) {
            printf("%.2f*x^%d", L.data[i].coef, L.data[i].expn);
        } else {
            printf(" + %.2f*x^%d", L.data[i].coef, L.data[i].expn);
        }
    }
    printf("\n");
}

void AddPoly(PolyList *La, PolyList Lb) {
    int i, j, k;
    i = j = k = 0;
    while (i < La->length && j < Lb.length) {
        if (La->data[i].expn == Lb.data[j].expn) {
            La->data[i].coef += Lb.data[j].coef;
            i++;
            j++;
        } else if (La->data[i].expn < Lb.data[j].expn) {
            i++;
        } else {
            for (int n = La->length - 1; n >= i; n--) {
                La->data[n + 1] = La->data[n];
            }
            La->data[i] = Lb.data[j];
            La->length++;
            i++;
            j++;
        }
    }
    while (j < Lb.length) {
        La->data[i++] = Lb.data[j++];
        La->length++;
    }
}

void MultiplyPoly(PolyList La, PolyList Lb, PolyList *Lc) {
    PolyNode temp[MAXSIZE];
    int i, j, k, n;
    float temp_coef;
    Lc->length = 0;
    for (i = 0; i < La.length; i++) {
        for (j = 0; j < Lb.length; j++) {
            temp_coef = La.data[i].coef * Lb.data[j].coef;
            n = La.data[i].expn + Lb.data[j].expn;
            temp[n].coef += temp_coef;
            temp[n].expn = n;
        }
    }
    for (k = 0; k < MAXSIZE; k++) {
        if (temp[k].coef != 0) {
            Lc->data[Lc->length] = temp[k];
            Lc->length++;
        }
    }
}

int main() {
    PolyList La, Lb, Lc;
    CreatePoly(&La);
    CreatePoly(&Lb);
    printf("\n");
    PrintPoly(La);
    PrintPoly(Lb);
    AddPoly(&La, Lb);
    printf("\n");
    PrintPoly(La);
    MultiplyPoly(La, Lb, &Lc);
    printf("\n");
    PrintPoly(Lc);
    return 0;
}

程序中使用了线性表来存储多项式，其中 `PolyNode` 结构体表示多项式的一项，`PolyList` 结构体表示整个多项式。程序中先输入两个多项式，然后将它们相加并输出，最后将它们相乘并输出。