c++类栈的复制构造函数，大侠帮我看看那里出错了

#include<iostream>
 using namespace std;
 class SqStack
 {
     private:
         typedef struct LNode
         {
             int data;
             struct LNode *next;
         }*Linklist,LNode;
         int count;
         Linklist L;
     public:
         SqStack();
         SqStack(SqStack &Sq);
         ~SqStack();
         void Push(int e);
         int Pop();
         int empty();
 };
 
inline SqStack :: SqStack()
 {
     count=0;
     L = NULL; //初始化指针成员以免出现拷贝异常
}
inline SqStack :: ~SqStack()
 {
     if(!empty())   //判断栈不为空
     {
         Linklist p = NULL;
         while(L)
         {
             p = L;
             L = L->next;
             delete p;
         }
     }
}
SqStack :: SqStack(SqStack &Sq)
 {   
     
     count=0;
     if(!Sq.empty())  //原构造函数 L 没初始化，执行q = Sq.L没意义
     {
         Linklist q;
         q=Sq.L;
         while(q)  //原函数逻辑反了
        {   
            if(count==0)
            {
                L=new LNode;
                L->data=q->data;
                L->next=NULL;
                count++;
            }
            else
            {
                Linklist p;
                p=new LNode;
                p->data=q->data;
                p->next=L;
                L=p;
                count++;
                q=q->next;
            }
            
        }
     }
     else L = NULL;
}
 void SqStack :: Push(int e)
 {   
     if(count==0)
     {
         L=new LNode;
         L->data=e;
         L->next=NULL;
         count++;
     }
     else
     {
         Linklist p;
         p=new LNode;
         p->data=e;
         p->next=L;
         L=p;
         count++;
     }
 }
 int SqStack :: Pop()
 {   
     Linklist p;
     int e;
     p=L;
     if(!p->next)
     {   
         e=p->data;
         delete p;
         count--;
     }
     else
     {
         p = L;
         L=L->next;
         e=p->data;
         delete p;
         count--;
     }
     return e;
 }
 int SqStack :: empty()
 {   
     if(count==0)
         return 1;
     else
         return 0;   
}
 int main()
 {
     SqStack S;
     SqStack T;
     SqStack W(T);
     int e;
     cout<<"请输入多个整数:"<<endl;
     cin>>e;
     while(e)
     {   
         if(e>0)
             S.Push(e);
         else
             T.Push(e);
         cin>>e;
     }
     cout<<"正整数："<<endl;
     while(!S.empty())
     {   
         int Q;
         Q=S.Pop();
         cout<<"   "<<Q;
     }
     cout<<endl;
     cout<<"负整数："<<endl;
     while(!T.empty())
     {   
         int Q;
         Q=T.Pop();
         cout<<"    "<<Q;
     }
     cout<<endl;
         while(!W.empty())
     {   
         int Q;
         Q=W.Pop();
         cout<<"   "<<Q;
     }
     return 0;
 
}

[ 本帖最后由 YueWuSS 于 2011-10-29 10:59 编辑 ]