实验三 间接寻址

#include<iostream>  
using namespace std;  
const int M=20;  
struct Node
{
	int data;
}; 
class Student
{  
    public:  
        Student();       
        Student(int a[],int n);   
		~Student(){}
        int Length(){return length;}
        int Get(int i);  
        int Delete(int i);
        void Insert(int i,int x);  
        void Print();  
    private:  
         Node *first[M];  
         int length;  
};  
Student::Student()      
{  
    for(int i=0;i<M;i++)  
    first[i]=NULL;  
    length=0;   
}    
Student::Student(int a[],int n)
{  
    for(int i=0;i<M;i++)  
    {  
        first[i]=new Node;  
        first[i]->data=a[i];  
    }  
    length=n;  
}  
int Student::Get(int i) 
{  
    if(i<1||i>length) 
		throw"位置非法";  
    else return first[i-1]->data;   
}   
int Student::Delete(int i)
{   
    int x,j;  
    if(length==0)
		throw"下溢";  
    if(i<1||i>length)
		throw"位置非法";  
    x=first[i-1]->data;  
    for(j=i;j<length;j++)  
    first[j-1]->data=first[j]->data;  
    length--;  
    return x;  
}   
void Student::Insert(int i,int x) 
{  
    int j;  
    if(length>=M)
		throw"上溢";  
    if(i<1||i>length+1)
		throw"位置非法";   
    for(j=length;j>=i;j--)  
    first[j]->data=first[j-1]->data;  
    first[i-1]->data=x;  
    length++;   
} 
void Student::Print() 
{  
    int i;   
    for( i=0;i<length;i++)  
    {         
        cout<<endl<<"第"<<i+1<<"个学生成绩"<<first[i]->data<<" ";  
    }  
}   
void main()
{
	int score[3]={90,60,85};
	Student S(score,3);
	cout<<"学生的成绩为："<<endl;
	S.Print();
	cout<<endl<<endl<<"在位置2插入成绩70："<<endl;
	S.Insert(2,70);
	S.Print();
	cout<<endl<<endl<<"删除第三个学生的成绩："<<endl;
	S.Delete(3);
	S.Print();
	cout<<endl<<endl<<"位置2的成绩为："<<endl;
	cout<<S.Get(2)<<endl;
	cout<<endl;
}