学生成绩双链表

#include<iostream.h>  
template<class T>  
struct Node  
{  
    T data;  
    Node<T>*next,*prior;  
};  
template<class T>  
class Student  
{  
    public:  
        Student();  
        Student(T a[],int n);  
        ~Student(); 
		int Count();
        int Locate(T x);  
        void Insert(int i,T x);  
        T Delete(int i);  
        void Print();  
    private:  
        Node<T>*first;  
};  
template<class T>
Student<T>::Count()
{
	Node<T> *r=new Node<T>;
	r=first->next;int count=0;
	while(r!=NULL)
	{
		r=r->next;
		count++;}
	return count;
}

template<class T>  
Student<T>::Student()  
{  
    first=new Node<T>;  
    first->next=NULL;  
}  
template<class T>  
Student<T>::Student(T a[],int n)  
{  
    Node<T> *r,*s;  
    first=new Node<T>;  
    r=first;  
    for(int i=0;i<n;i++)  
    {  
        s=new Node<T>;  
        s->data=a[i];
		s->prior=r;
        r->next=s;r=s;  
    }  
    r->next=NULL;  
}  
template<class T>  
Student<T>::~Student()  
{  
    Node<T> *q=NULL;  
    while(first!=NULL)  
    {  
        q=first;  
        first=first->next;  
        delete q;  
    }  
}  
template<class T>  
void Student<T>::Insert(int i,T x)  
{  
    Node<T>*p=first,*s=NULL;  
    int count=0;  
    while(p!=NULL&&count<i-1)  
    {  
        p=p->next;  
        count++;  
    }  
    if(p==NULL)throw"位置";  
    else{  
        s=new Node<T>;s->data=x;
		s->prior=p;
        s->next=p->next;p->next->prior=s;
		p->next=s;
    }  
}  
template<class T>  
T Student<T>::Delete(int i)  
{  
    Node <T>*p=first,*q=NULL;  
    T x;  
    int count=0;  
    while(p!=NULL&&count<i-1)  
    {  
        p=p->next;  
        count++;  
    }  
    if(p==NULL||p->next==NULL)  
        throw"位置";  
    else  
    {  
        p->prior->next=p->next;
		p->next->prior=p->prior;
        delete q;  
        return x;  
    }  
}  
template<class T>  
int Student<T>::Locate(T x)  
{  
    Node<T> *p=first->next;  
    int count=1;  
    while(p!=NULL)  
    {  
        if(p->data==x)return count;  
        p=p->next;  
        count++;  
    }  
    return 0;  
}  
template<class T>  
void Student<T>::Print()  
{  
    Node<T>*p=first->next;  
    while(p!=NULL)  
    {  
        cout<<p->data<<" ";  
        p=p->next;  
    }  
    cout<<endl;  
}  
void main()  
{  
    float r[5]={91,92,93,94,95};  
    Student<float>L(r,5);  
    cout<<"一共有"<<L.Count()<<"学生成绩"<<endl; 
    L.Print();  
    cout<<"在第3位插入一个分数为100的学生"<<endl;  
    L.Insert(4,100);  
    cout<<"插入后一共有"<<L.Count()<<"学生成绩"<<endl;  
    L.Print();  
    cout<<"分数为93的学生位置为";  
    cout<<L.Locate(93)<<endl;  
    cout<<"执行删除第二个学生分数的操作，删除前数据为："<<endl;  
    L.Print();  
    L.Delete(2);  
    cout<<"删除后数据为："<<endl;  
    L.Print();
}