В чем ошибка программы

#include <iostream>
#include <iomanip>
#include <algorithm>
#include <string>
#include <fstream>
 
using namespace std;
 
class Student {
  string f_name, s_name, fathership;
  double meanGrade;
 
 protected:
  int grade, trait;
  vector<int> grades{};
 
 public:
  Student(int quantity_grades = 0,
          string f_n = "",
          string s_n = "",
          string fath = "");
  Student(string file_name);
  ~Student();
  string getFN();
  string getSN();
  string getFSHIP();
  int getTrait();
  int getGrade();
  void setStudent(string f_n, string s_n, string fath, vector<int> grs);
  void setStudent(Student& s);
  void MeanGrade();
  virtual void setTrait();
};
 
Student::Student(int quantity_grades, string f_n, string s_n, string fath)
    : f_name(f_n),
      s_name(s_n),
      fathership(fath),
      meanGrade(0),
      grade(0),
      trait(0) {
  grades.resize(quantity_grades);
}
 
Student::Student(string file_name) {
  cout << file_name << endl;
  int quantity_grades;
  ifstream inf(file_name);
  if (inf.bad()) {
    cerr << "ERROR" << endl;
 
  } else {
    inf >> f_name >> s_name >> fathership;
    inf >> quantity_grades;
    for (int i = 0; i < quantity_grades; ++i) {
      inf >> grades[i];
    }
 
    inf.close();
  }
}
 
Student::~Student() {
  cout << "student za endo" << endl;
  grades.clear();
}
 
void Student::setStudent(string f_n, string s_n, string fath, vector<int> grs) {
  f_name = f_n;
  s_name = s_n;
  fathership = fath;
  int i = 0;
  grades.resize(grs.size());
  for (auto& element : grs) {
    grades[i] = element;
    ++i;
  }
}
 
inline string Student::getFN() {
  return f_name;
}
 
inline string Student::getSN() {
  return s_name;
}
 
inline string Student::getFSHIP() {
  return fathership;
}
 
inline int Student::getTrait() {
  return trait;
}
 
// inline double Student::getMean() {
// return meanGrade;
//}
 
inline int Student::getGrade() {
  return grade;
}
 
void Student::MeanGrade() {
  double s = 0;
  for (auto& element : grades) {
    s += element;
  }
  meanGrade = double(s / grades.size());
  grade = meanGrade + 0.5;
  cout << meanGrade << endl;
  cout << grade << endl;
}
 
void Student::setTrait() {
  cout << "Student " << trait << endl;
}
 
class Student5 : public Student {
 public:
  Student5(int quantity_grades = 0,
           string f_n = "",
           string s_n = "",
           string fath = "");
  Student5(string file_name);
  ~Student5();
  void setTrait();
};
 
Student5::Student5(int quantity_grades, string f_n, string s_n, string fath)
    : Student(quantity_grades, f_n, s_n, fath) {}
 
Student5::Student5(string file_name) : Student(file_name) {}
 
Student5::~Student5() {
  cout << "student5 za endo" << endl;
}
 
void Student5::setTrait() {
  trait = grade;
  cout << "Student5 " << trait << endl;
}
 
class Student10 : public Student {
 public:
  Student10(int quantity_grades = 0,
            string f_n = "",
            string s_n = "",
            string fath = "");
  Student10(string file_name);
  ~Student10();
  void setTrait();
};
 
Student10::Student10(int quantity_grades, string f_n, string s_n, string fath)
    : Student(quantity_grades, f_n, s_n, fath) {}
 
Student10::Student10(string file_name) : Student(file_name) {}
 
Student10::~Student10() {
  cout << "student10 za endo" << endl;
}
 
void Student10::setTrait() {
  if (grade >= 9) {
    trait = 5;
  } else if (grade >= 6) {
    trait = 4;
  } else if (grade >= 4) {
    trait = 3;
  } else {
    trait = 2;
  }
 
  cout << "Student10 " << trait << endl;
}
 
int main() {
  setlocale(LC_ALL, "RUS");
  Student* students[10];
  students[0] = new Student5();
  vector<int> v0{5, 3, 4, 2, 5};
  (*students[0]).setStudent("Даниил", "Варов", "Юрьевич", v0);
  (*students[0]).MeanGrade();
  students[0]->setTrait();
  cout << endl;
  students[1] = new Student10();
  vector<int> v1{5, 5, 9, 4, 4};
  (*students[1]).setStudent("Наруто", "Нарутов", "Нарутович", v1);
  (*students[1]).MeanGrade();
  students[1]->setTrait();
  cout << endl;
  students[2] = new Student5("Student1.txt");
 
  (*students[2]).MeanGrade();
  students[2]->setTrait();
  students[2]->getFN();
 
  return 0;
}

#include <vector>