异构列表和动态数组分配

所以我在填充这个异构列表时遇到了问题。我传入一个文本文件，并使用它来填充对象的成员数据，然后将它们添加到列表中。这是我第一次使用它，我不明白为什么它不能正常工作。它应该将每个填充的对象地址保存到指针数组中的一个指针，对吗？然而，当我测试它时，我可以看到它只保存到（*list）[0]的单个位置。最相关的部分可能来自main.cpp。谢谢！

main.cpp

#include <iostream>
#include <fstream>
#include <string>
#include <iomanip>
#include "student.h"
using namespace std;
int main()
{
    string inputFileName;
    string outputFileName;
    cout << "Please enter the input file name: ";
    getline(cin, inputFileName);
    ifstream inputFile;
    int NUMBEROFENTRIES;
    inputFile.open(inputFileName.c_str());   //CLOSE
    if(inputFile){
        NUMBEROFENTRIES = int(inputFile.get())-int('0');
    }else{
        cout << "Failed to open file." << endl;
    }
    Student ** list; //create a pointer to Student pointer
    list = new Student*[NUMBEROFENTRIES];  //dynamically allocated list of Student pointers
    for(int i = 0; i < NUMBEROFENTRIES; i++) 
    {
        string uselessNewLine;
        getline(inputFile, uselessNewLine);
        string tempfirstname;
        string templastname;
        getline(inputFile, templastname, ',');
        inputFile.get();
        getline(inputFile, tempfirstname);
        char tempcourse = inputFile.get();
        if(tempcourse == 'b'||tempcourse == 'B')
        {
            BioStudent bobj;
            bobj.setNameAndCourse(tempfirstname, templastname, tempcourse);
            string garbage;
            getline(inputFile, garbage, ' ');
            bobj.SetGrades(inputFile);
            list[i] = &bobj; //I assume this is where the error is but i should be incrementing?
        }
        else if(tempcourse == 't' || tempcourse == 'T')
        {
            TheaterStudent tobj;
            tobj.setNameAndCourse(tempfirstname, templastname, tempcourse);
            string garbage;
            getline(inputFile, garbage, ' ');
            tobj.SetGrades(inputFile);
            list[i] = &tobj;  //I assume this is where the error is but i should be incrementing?

        }
        else if(tempcourse == 'c' || tempcourse == 'C')
        {
            CompsciStudent cobj;
            cobj.setNameAndCourse(tempfirstname, templastname, tempcourse);
            string garbage;
            getline(inputFile, garbage, ' ');
            getline(inputFile, garbage, ' ');
            cobj.SetGrades(inputFile);
            list[i] = &cobj;  //I assume this is where the error is but i should be incrementing?

        }else{
            cout << "ERROR" << endl;
        }
        cout << (*list[0]).course << endl;
    }

    delete [] list;
    return 0;
}

学生.h

#include <string>
#include <iostream>
using namespace std;

class Student
{
public:
    virtual double GetAverage()=0;  //Another pure virtual function
    void setNameAndCourse(string fn, string ln, char tc);
    Student();
    char course;
    char GetCourse();
protected:
    string firstName;
    string lastName;

private:
};

class BioStudent: public Student
{
public:
    BioStudent();
    void SetGrades(ifstream &input);
    double GetAverage();
private:
    int labGrade;
    int test1;
    int test2;
    int test3;
    int finalExam;
};

class TheaterStudent: public Student
{
public:
    TheaterStudent();
    void SetGrades(ifstream &input);
    double GetAverage();
private:
    int participation;
    int midterm;
    int finalExam;
};

class CompsciStudent: public Student
{
public:
    CompsciStudent();
    void SetGrades(ifstream &input);
    double GetAverage();
private:
    int assign1;
    int assign2;
    int assign3;
    int assign4;
    int assign5;
    int assign6;
    double assignAverage;
    int test1;
    int test2;
    int finalExam;
};

学生.cpp

#include "student.h"
#include <iostream>
#include <iomanip>
#include <string>
#include <fstream>
using namespace std;
Student::Student()
{
    firstName = "";
    lastName = "";
    course = ' ';
}
void Student::setNameAndCourse(string fn, string ln, char tc)
{
    firstName = fn;
    lastName = ln;
    course = tc;
}
char Student::GetCourse()
{
    return course;
}
BioStudent::BioStudent()
{
    labGrade = 0;
    test1 = 0;
    test2 = 0;
    test3 = 0;
    finalExam = 0;
}
void BioStudent::SetGrades(ifstream& input)  
{
    input >> labGrade;
    input >> test1;
    input >> test2;
    input >> test3;
    input >> finalExam;
}
double BioStudent::GetAverage()
{
    double toReturn = 0.0;
    toReturn = ((labGrade*.3) + (test1*.15) + (test2*.15) + (test3*.15) + (finalExam*.25));
    return toReturn;
}
TheaterStudent::TheaterStudent()
{
    participation = 0;
    midterm = 0;
    finalExam = 0;
}
void TheaterStudent::SetGrades(ifstream &input) 
{
    input >> participation;
    input >> midterm;
    input >> finalExam;
}
double TheaterStudent::GetAverage()
{
    double toReturn = 0.0;
    toReturn = ((participation*.4)+(midterm*.25)+(finalExam*.35));
    return toReturn;
}
CompsciStudent::CompsciStudent()
{
    assign1 = 0;
    assign2 = 0;
    assign3 = 0;
    assign4 = 0;
    assign5 = 0;
    assign6 = 0;
    assignAverage = 0.0;
    test1 = 0;
    test2 = 0;
    finalExam = 0;
}
void CompsciStudent::SetGrades(ifstream &input)
{
    input >> assign1;
    input >> assign2;
    input >> assign3;
    input >> assign4;
    input >> assign5;
    input >> assign6;
    input >> test1;
    input >> test2;
    input >> finalExam;
}
double CompsciStudent::GetAverage()
{
    double toReturn = 0.0;
    assignAverage = ((assign1+assign2+assign3+assign4+assign5+assign6)/6);
    toReturn = ((assignAverage*.3)+(test1*.2)+(test2*.2)+(finalExam*.3));
    return toReturn;
}