一元多项式的表示及相加的C语言具体代码

一元多项式可以使用结构体来表示，其中结构体包括两个成员变量，一个是系数，另一个是指数。下面是一元多项式的结构体定义：

typedef struct node {
    float coef; // 系数
    int expn;   // 指数
    struct node *next;
} Polynomial;

其中，`next` 是指向下一个结点的指针，可以用来构造链表。

下面是一元多项式相加的具体代码实现：

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

typedef struct node {
    float coef; // 系数
    int expn;   // 指数
    struct node *next;
} Polynomial;

// 生成多项式
Polynomial *create() {
    Polynomial *p, *r, *head;
    head = (Polynomial*)malloc(sizeof(Polynomial));
    head->next = NULL;
    r = head;
    int n, i;
    float c;
    printf("请输入多项式的项数：");
    scanf("%d", &n);
    for (i = 1; i <= n; i++) {
        printf("请输入第%d项的系数和指数：", i);
        scanf("%f %d", &c, &e);
        p = (Polynomial*)malloc(sizeof(Polynomial));
        p->coef = c;
        p->expn = e;
        p->next = NULL;
        r->next = p;
        r = p;
    }
    return head;
}

// 多项式相加
Polynomial *add(Polynomial *pa, Polynomial *pb) {
    Polynomial *pc, *qa, *qb, *p, *q, *t;
    pc = (Polynomial*)malloc(sizeof(Polynomial));
    pc->next = NULL;
    qa = pa->next;
    qb = pb->next;
    p = pc;
    while (qa && qb) {
        if (qa->expn < qb->expn) {
            t = (Polynomial*)malloc(sizeof(Polynomial));
            t->coef = qa->coef;
            t->expn = qa->expn;
            t->next = NULL;
            p->next = t;
            p = t;
            qa = qa->next;
        } else if (qa->expn > qb->expn) {
            t = (Polynomial*)malloc(sizeof(Polynomial));
            t->coef = qb->coef;
            t->expn = qb->expn;
            t->next = NULL;
            p->next = t;
            p = t;
            qb = qb->next;
        } else {
            t = (Polynomial*)malloc(sizeof(Polynomial));
            t->coef = qa->coef + qb->coef;
            t->expn = qa->expn;
            t->next = NULL;
            p->next = t;
            p = t;
            qa = qa->next;
            qb = qb->next;
        }
    }
    while (qa) {
        t = (Polynomial*)malloc(sizeof(Polynomial));
        t->coef = qa->coef;
        t->expn = qa->expn;
        t->next = NULL;
        p->next = t;
        p = t;
        qa = qa->next;
    }
    while (qb) {
        t = (Polynomial*)malloc(sizeof(Polynomial));
        t->coef = qb->coef;
        t->expn = qb->expn;
        t->next = NULL;
        p->next = t;
        p = t;
        qb = qb->next;
    }
    return pc;
}

// 输出多项式
void print(Polynomial *p) {
    Polynomial *q = p;
    while (q->next) {
        q = q->next;
        printf("%.2fx^%d", q->coef, q->expn);
        if (q->next) {
            printf(" + ");
        }
    }
    printf("\n");
}

int main() {
    Polynomial *pa, *pb, *pc;
    printf("请输入第一个多项式：\n");
    pa = create();
    printf("请输入第二个多项式：\n");
    pb = create();
    pc = add(pa, pb);
    printf("相加后的多项式为：\n");
    print(pc);
    return 0;
}

此代码中使用了单链表来存储多项式，`create` 函数用来生成多项式，`add` 函数用来实现多项式相加，`print` 函数用来输出多项式。