有没有大佬帮忙看一下哪里出现了问题，编译没有错误却无法输出，知道的麻烦帮一下吧，多谢了！

#include<stdio.h>
#include<malloc.h>
typedef struct Polynode
{
    int coef;
    int exp;
    struct Polynode *next;
}Polynode,*Polylist;
Polylist PolyCreate();
void polyadd(Polylist polya,Polylist polyb);
void output(Polylist poly);



Polylist PolyCreate()
{
    Polynode *head,*rear,*s;
    int c,e;
    head=(Polynode *)malloc(sizeof(Polynode));
    rear=head;
    printf("输入系数与指数，系数为零时结束\n");
    scanf("%d,%d",&c,&e);
    while(c!=0)
    {
        s=(Polynode *)malloc(sizeof(Polynode));
        s->coef=c;
        s->exp=e;
        rear->next=s;
        rear=s;
        scanf("%d,%d",&c,&e);   
    }
    rear->next=NULL;
    return(head);
}


void output(Polylist poly)
{
    Polynode *p;
    p=(Polynode *)malloc(sizeof(Polynode));
    p=poly->next;
    while(p!=NULL)
    {
        if(p->exp=0)
        {
            if(p->coef>0)
            printf("+%d",p->coef);
            else
            printf("%d",p->coef);
        }
        if(p->exp>0)
        {
            if(p->coef>0)
            printf("+%d*x^%d",p->coef,p->exp);
            else
            printf("%d*x^%d",p->coef,p->exp);
        }
        p=p->next;
    }
}






void polyadd(Polylist polya,Polylist polyb)
{
    Polynode *p,*q,*tail,*temp;
    int sum;
    p=polya->next;
    q=polyb->next;
    tail=polya;
    while(p!=NULL&&q!=NULL)
    {
        if(p->exp<q->exp)
        {
            tail->next=p;
            tail=p;
            p=p->next;
        }
        else if(p->exp==q->exp)
        {
            sum=p->coef+q->coef;
            if(sum!=0)
            {
                p->coef=sum;
                tail->next=p;
                tail=p;
                p=p->next;
                temp=q;
                q=q->next;
                free(temp);
            }
            else
            {
                temp=p;
                p=p->next;
                free(temp);
                temp=q;
                q=q->next;
                free(temp);
            }
        }
         else
         {
             tail->next=q;
             tail=q;
             q=q->next;
         }
    }
    if(p!=NULL)
    tail->next=p;
    else
    tail->next=q;
}
int main()
{
    Polynode *a,*b;

    a=PolyCreate();
    output(a);
    b=PolyCreate();
    output(b);
    polyadd(a,b);
    output(a);
    return (0);
     
}