我试图为我的c ++程序设置文件阅读器和矢量，但不知道如何做到这一点

Question

正如标题所示，我有一个学生班，有一个本科的派生班。程序必须从文本文件中读取并实例化一个底层对象。之后，它必须创建一个从文本文件中实例化的对象列表。这是我的第一个C ++项目，对初学者来说相当麻烦。我只需要知道如何从这里开始。这是代码

#include <fstream>
#include <iostream>;
#include <vector>
using namespace std;
 class Student {
  protected:
   char name[21];
   char ssn[10];
   float gpa;
   int credits;

 public:
  Student::Student() {};

  Student(const char n[], const char ss[], float gp, int cred) {
    strcpy_s(name, sizeof(name), n);
    strcpy_s(ssn, sizeof(ssn), ss);
    gpa = gp;
    credits = cred;


  }


virtual void print() {
    cout << "Name: " << name << endl;
    cout << "SSN: " << ssn << endl;
    cout << "GPA: " << gpa << endl;
    cout << "Credits: " << credits << endl;
}
virtual float tuition() const = 0;


     };
 class undergrad : public Student {
  protected:
   float undergrad_rate = 380;
    char* year;
  public:
   undergrad::undergrad() {};

    undergrad( const char n[], const char ss[], char* yr,int cred, float gp) 
      :
    Student(n, ss, gp, cred),year(yr) {}

    void set_year(char* yr) {
     year = yr;
   }
    char* getYear() {
     return year;
   }
    float getRate() {
     return undergrad_rate;
    }
    void print() {
     Student::print();
     cout << "Undergrad rate: " << undergrad_rate << endl;
     cout << "year: " << year << endl;


    }

   float tuition() const {
    //cout << "The tuition is $35000" << endl;
    return 35000;
     }


 int main() {



  system("pause");






    return 0;

 }

此外，我想知道文件方法本身就是一个扩展到undergrad的类。