这个创建一元多项式的程序怎么运行不了啊？

#include <iostream>
using namespace std;
typedef struct{
    float coef;
    int expn;
}term,ElemType;
typedef struct LNode{
    ElemType data;
    struct LNode *next;
}LNode,*LinkList;
typedef LinkList polynomial;
void InitList_L(LinkList &head)
{
    head=new LNode;
    head->next=NULL;
}
void CreatPolyn(polynomial &P,int m);void CreatPolyn(polynomial &P,int m)
{
    InitList_L(P);
    polynomial q1,q2;
    term e;
    P->data.coef=0.0;P->data.expn=-1;
    q1=P;
    for(int i=1;i<=m;i++)
    {
        cin>>e.coef>>e.expn;
        while(e.expn>q1->next->data.expn&&q1->next)
            q1=q1->next;
        q2=new LNode;
        q2->data.coef=e.coef;q2->data.expn=e.expn;
        q2->next=q1->next;q1->next=q2;
    }
}
void PrintPolyn(polynomial P)
{
    while(P->next!=NULL)
    {
        cout<<"("<<P->data.coef<<","<<P->data.expn<<")  ";
        P=P->next;
    }
    cout<<endl;
}
int main()
{
    polynomial pa,pb;
    CreatPolyn(pa,4);CreatPolyn(pb,6);
    cout<<"output pa:"<<endl;
    PrintPolyn(pa);
    cout<<"output pb:"<<endl;
    PrintPolyn(pb);
    return 0;
}