#include <iostream>
using namespace std;
typedef struct node
{
    float coef;//系数域
    int exp;//指数域
    struct node *next;

}polynode;
//创建
polynode *init_polynode()
{
    int c=0,e=0;
    polynode *p=NULL,*q=NULL,*r=NULL;
    p=new polynode;
    r=p;
    cout<<"请按指数的升降次序输入系数和指数："<<endl;
    cin>>c>>e;
    while(c!=0)
    {
       q=new polynode;
       q->coef=c;
       q->exp=e;
       r->next=q;
       r=q;
       cin>>c>>e;
    }
    if(r!=NULL)
       r->next=NULL;
    return p;
   
}
void sort(polynode *L,int n){       //冒泡排序
 polynode *p,*q;
 p=L->next;
 q=p->next;
 int i,j,t,k;
 for(j=0;i<n-1;j++)
 {
  for(i=0;i<n-j-1;i++)
  {
   if(p->exp>q->exp)
   {
    t=p->exp;
    p->exp=q->exp;
    q->exp=t;
    k=p->coef;
    p->coef=q->coef;
    q->coef=k;
   }//if
      p=p->next;
   q=q->next;
  }//for
 }//for
}//PaixuF

//相加
polynode *add_polynode(polynode *pa, polynode *pb)
{
    polynode *head, *t, *s,*p1,*p2;
    int v;
    p1=pa->next;
    p2=pb->next;
    t=pa;
    head=t;
    while(p1&&p2)
    {
       if(p1->exp==p2->exp)
       {
          v=p1->coef+p2->coef;
          if(v!=0)
          {
             p1->coef=v;
             t->next=p1;
             t=t->next;
             p1=p1->next;
             s=p2;
             p2=p2->next;
             delete s;
          }
          else
          {
              s=p1->next;delete p1;p1=s;
              s=p2->next;delete p2;p2=s;
          }
       }
       else if(p1->exp<p2->exp)
       {
           t->next=p1;
           t=t->next;
           p1=p1->next;
       }
       else
       {
           t->next=p2;
           t=t->next;
           p2=p2->next;
       }
    }
     if(p1)
         t->next=p1;
     else
         t->next=p2;

     return head;
}
void print_polynode(polynode *head)
{
    polynode *p=NULL;
    p=head->next;
    if(p==NULL)
        cout<<"多项式为NULL;"<<endl;
    else
    {
       while(p!=NULL)
       {
           if(p->coef>=0)
             cout<<"+"<<p->coef<<"x^"<<p->exp;
           else
              cout<<p->coef<<"x^"<<p->exp;
           p=p->next;

       }
       cout<<endl;
    }

   

}

int main()
{
 polynode *heada=NULL,*headb=NULL,*headsum=NULL;
 int m,n;
 cout<<"建立第一个函数："<<endl;
 cout<<"请输入多项式项数：";
 cin>>m;
 heada=init_polynode();
 cout<<"第一个函数："<<endl;
 sort(heada,m);
 print_polynode(heada);
 cout<<"建立第二个函数："<<endl;
 cout<<"请输入多项式项数：";
 cin>>n;
 headb=init_polynode();
 cout<<"第二个函数："<<endl;
 sort(headb,n);
 print_polynode(headb);
 headsum=add_polynode(heada,headb);
 cout<<"函数和为："<<endl;
 print_polynode(headsum);
 return 0;
}



我的这个程序当有一个多项式为0时不能输出结果，不知道该怎么改？