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。

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(); 
}