迭代器模式——C++实现

问题描述：

信1305班共44名同学，每名同学都有姓名，学号和年龄等属性，分别使用JAVA内置迭代器和C++中标准模板库（STL）实现对同学信息的遍历，要求按照学号从小到大和从大到小两种次序输出学生信息。

C++代码：

#include <string>
#include <vector>
#include <iostream>
#include <fstream>
using namespace std;
struct student
{
	string id;
	string name;
}; 
void LoadStudent(vector<student>&); 
int main()
{
	vector<student> v,v1;
	LoadStudent(v);
	LoadStudent(v1);
	cout<<"学号从小到大："<<endl;
	for (vector<student>::iterator iter = v.begin(); iter != v.end(); ++iter)
	{
		cout << "学号:" << iter->id << "  姓名:" << iter->name << endl;
	}
	cout<<"***********************"<<endl;
	cout<<"学号从大到小："<<endl;
	for (vector<student>::reverse_iterator iter1 = v.rbegin(); iter1 != v.rend(); ++iter1)
	{
		cout << "学号:" << iter1->id << "  姓名:" << iter1->name << endl;
	}
	return 0;
}
void LoadStudent(vector<student>& v)
{
	ifstream infile;
	infile.open("E:\\student.txt");
	student s;
	if(!infile)     //判断是否存在ifstream infile  
    {  
        cout<<"读入文件不存在"<<endl;  
    }  
    if (infile.is_open())   //判断文件流是否处于打开状态  
    {  
        while (infile.good()&&!infile.eof())  
        {  
			infile>>s.id>>s.name;  
            v.push_back(s);    //将数据读入到data_vector  
        }  
    }  
    infile.close();  
}

　　

运行结果：