#include<stdio.h>
#include<malloc.h>
#include<math.h>
#define LEN sizeof(struct polynomial)



int i,j;


struct polynomial          //多项式单个式子的结构体
{
    int coff;
    int index;
    struct polynomial* next;
};






void main()                         //主函数
{
    struct polynomial* create();
    void print(struct polynomial* h);
    struct polynomial* add(struct polynomial* m,struct polynomial* n);
    struct polynomial *head1;                           //第一个多项式头指针
    struct polynomial *head2;                           //第二个多项式头指针
    struct polynomial *headadd;                         //加法计算过之后多项式头指针
    printf("输入第一个多项式：\n");   
    head1=create();
    printf("第一个多项式为：\n");
    print(head1);
    printf("输入第二个多项式：\n");
    head2=create();
    printf("第二个多项式为：\n");
    print(head2);
    printf("进行加法运算：\n");
    headadd=add(head1,head2);
    printf("加法运算结果为：\n");
    print(headadd);
}





struct polynomial* create()                //动态链表创建函数
{
    int n=0;
    struct polynomial *head,*p1,*p2;
    p1=p2=(struct polynomial*)malloc(LEN); //分配LEN空间
    scanf("%d %d",&p1->coff,&p1->index);
    head=NULL;
    while(p1->coff!=0)                     //手动输入0结束此循环（多项式输入结束标志）
    {
        n++;
        if(n==1)
            head=p1;
        else
            p2->next=p1;
        p2=p1;
        p1=(struct polynomial*)malloc(LEN);
        scanf("%d %d",&p1->coff,&p1->index);
    }
    p2->next=NULL;                            //标志动态链表到此结束
    return(head);
}



void print(struct polynomial *h)                 //链表输出函数
{
    struct polynomial* p;
    p=h;                                          //保存链表头指针
    while(p->next!=NULL)
    {
        printf("%dx^%d+",p->coff,p->index);
        p=p->next;
        if(p->next==NULL)
            printf("%dx^%d",p->coff,p->index);
    }
    printf("\n");

}




struct polynomial* add(struct polynomial* m,struct polynomial* n)   //加法运算
{
    struct polynomial *p1,*p2;
    struct polynomial *top,*end,*head;
    head=top=end=(struct polynomial*)malloc(LEN);
    p1=m;                                                            //保存链表头指针
    p2=n;
    while(p1->next!=NULL)                                            
    {
        while(p2->next!=NULL)
        {
            if(p1->index>p2->index)                              
            {
                top->index=p1->index;
                top->coff=p1->coff+p2->coff;
                top=(struct polynomial*)malloc(LEN);
                end->next=top;
                p2=p2->next;
                continue;
            }
            if(p1->index<p2->index)
            {
                top->index=p1->index;
                top->coff=p1->coff+p2->coff;
                top=(struct polynomial*)malloc(LEN);
                end->next=top;
                p2=p2->next;
                break;
            }
            if(p1->index==p2->index)
            {
                top->index=p1->index;
                top->coff=p1->coff+p2->coff;
                top=(struct polynomial*)malloc(LEN);
                end->next=top;
                p2=p2->next;
                break;
            }
        }
        p1=p1->next;
        if(p1->next==NULL)
        {
            while(p2->next!=NULL)                         //多项式二大于多项式一
            {
                top->index=p1->index;
                top->coff=p1->coff+p2->coff;
                top=(struct polynomial*)malloc(LEN);
                end->next=top;
                p2=p2->next;
            }
        }
        end->next=NULL;
    }
    return(head);
}

补充下：实现加法时出错没结果，创建和输出函数没问题！