一元多项式的乘法与加法运算，C语言完整代码

以下是一元多项式的乘法与加法运算的 C 语言完整代码：

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

struct node {
    int coef; // 系数
    int exp;  // 指数
    struct node *next;
};

typedef struct node LinkNode;
typedef LinkNode *LinkList;

// 创建多项式
void create_polynomial(LinkList *L) {
    int coef, exp;
    LinkNode *p, *r = *L;
    printf("请输入一元多项式的系数和指数（输入0 0结束）：\n");
    scanf("%d %d", &coef, &exp);
    while (coef != 0 || exp != 0) {
        p = (LinkNode *)malloc(sizeof(LinkNode));
        p->coef = coef;
        p->exp = exp;
        r->next = p;
        r = p;
        printf("请输入一元多项式的系数和指数（输入0 0结束）：\n");
        scanf("%d %d", &coef, &exp);
    }
    r->next = NULL;
}

// 输出多项式
void print_polynomial(LinkList L) {
    LinkNode *p = L->next;
    while (p) {
        if (p->exp == 0)
            printf("%d", p->coef);
        else if (p->exp == 1)
            printf("%dx", p->coef);
        else
            printf("%dx^%d", p->coef, p->exp);
        p = p->next;
        if (p)
            printf(" + ");
    }
    printf("\n");
}

// 多项式相加
void add_polynomial(LinkList A, LinkList B, LinkList *C) {
    LinkNode *pa = A->next, *pb = B->next;
    LinkNode *pc, *rc = (LinkNode *)malloc(sizeof(LinkNode));
    *C = rc;
    while (pa && pb) {
        if (pa->exp == pb->exp) {
            int sum = pa->coef + pb->coef;
            if (sum != 0) {
                pc = (LinkNode *)malloc(sizeof(LinkNode));
                pc->coef = sum;
                pc->exp = pa->exp;
                rc->next = pc;
                rc = pc;
            }
            pa = pa->next;
            pb = pb->next;
        } else if (pa->exp > pb->exp) {
            pc = (LinkNode *)malloc(sizeof(LinkNode));
            pc->coef = pa->coef;
            pc->exp = pa->exp;
            rc->next = pc;
            rc = pc;
            pa = pa->next;
        } else {
            pc = (LinkNode *)malloc(sizeof(LinkNode));
            pc->coef = pb->coef;
            pc->exp = pb->exp;
            rc->next = pc;
            rc = pc;
            pb = pb->next;
        }
    }
    while (pa) {
        pc = (LinkNode *)malloc(sizeof(LinkNode));
        pc->coef = pa->coef;
        pc->exp = pa->exp;
        rc->next = pc;
        rc = pc;
        pa = pa->next;
    }
    while (pb) {
        pc = (LinkNode *)malloc(sizeof(LinkNode));
        pc->coef = pb->coef;
        pc->exp = pb->exp;
        rc->next = pc;
        rc = pc;
        pb = pb->next;
    }
    rc->next = NULL;
}

// 多项式相乘
void multiply_polynomial(LinkList A, LinkList B, LinkList *C) {
    LinkNode *pa = A->next, *pb, *pc, *pd, *rd = (LinkNode *)malloc(sizeof(LinkNode));
    *C = rd;
    while (pa) {
        pb = B->next;
        pc = (LinkNode *)malloc(sizeof(LinkNode));
        if (!pc) {
            printf("内存分配失败！\n");
            exit(1);
        }
        pc->coef = pa->coef;
        pc->exp = pa->exp;
        pc->next = NULL;
        pd = rd;
        while (pb) {
            int coef = pa->coef * pb->coef;
            int exp = pa->exp + pb->exp;
            while (pd->next && pd->next->exp > exp)
                pd = pd->next;
            if (pd->next && pd->next->exp == exp) {
                if (pd->next->coef + coef != 0)
                    pd->next->coef += coef;
                else {
                    LinkNode *temp = pd->next;
                    pd->next = temp->next;
                    free(temp);
                }
            } else {
                LinkNode *temp = (LinkNode *)malloc(sizeof(LinkNode));
                if (!temp) {
                    printf("内存分配失败！\n");
                    exit(1);
                }
                temp->coef = coef;
                temp->exp = exp;
                temp->next = pd->next;
                pd->next = temp;
            }
            pb = pb->next;
            pd = rd;
        }
        pa = pa->next;
    }
}

int main() {
    LinkList A, B, C;
    printf("请输入第一个多项式：\n");
    A = (LinkNode *)malloc(sizeof(LinkNode));
    A->next = NULL;
    create_polynomial(&A);
    printf("第一个多项式为：");
    print_polynomial(A);
    printf("请输入第二个多项式：\n");
    B = (LinkNode *)malloc(sizeof(LinkNode));
    B->next = NULL;
    create_polynomial(&B);
    printf("第二个多项式为：");
    print_polynomial(B);
    add_polynomial(A, B, &C);
    printf("两个多项式相加为：");
    print_polynomial(C);
    multiply_polynomial(A, B, &C);
    printf("两个多项式相乘为：");
    print_polynomial(C);
    return 0;
}

这段代码实现了创建多项式、输出多项式、多项式相加和多项式相乘四个功能。其中，多项式相加使用了链表的合并排序思想，多项式相乘使用了链表的插入排序思想。