Done_laba

#include <iostream>
#include <string>
#include <fstream>
#include <Windows.h>

using namespace std;

struct Student {
    string name{};
    string surname{};
    string patronymic{};
    int number_group{};
    int birthYear{};
    int physics{};
    int math{};
    int informatics{};
    int chemistry{};
    double gap = (physics + math + informatics + chemistry) / 4.;
};


int strCounter()
{
    ifstream fin("File.txt", ios::in | ios::app);
    char * str = new char[256];
    int ans = 0;
    while (!fin.eof())
    {
        fin.getline(str, 256, '\n');
        ans++;
    }
    fin.close();
    delete[] str;
    return ans-1;
}

bool isGood(Student &s)
{
    if (s.informatics > 4 && s.math > 4)
        return true;
    return false;
}

void menu();

void push_back(Student *&students, Student &s, int &quantity)
{
    quantity++;
    Student *arr = new Student[quantity];
    for (int i = 0; i < quantity-1; i++)
    {
        arr[i] = students[i];
    }
    arr[quantity - 1] = s;
    students = arr;
}

void add(Student *&students, int &quantity) {
    ofstream fout("File.txt", ios::app);
    Student student;
    string temp;
    int temp_int = 0;
    int middle = 0;
    cout << "Enter name : ";
    cin >> temp;
    student.name = temp;
    fout << temp << " ";
    cout << "Enter surname : ";
    cin >> temp;
    student.surname = temp;
    fout << temp << " ";
    cout << "Enter patronymic : ";
    cin >> temp;
    student.patronymic = temp;
    fout << temp << " ";
    cout << "Enter number of group : ";
    cin >> temp_int;
    student.number_group = temp_int;
    fout << temp_int << " ";
    cout << "Enter year of birth : ";
    cin >> temp_int;
    student.birthYear = temp_int;
    fout << temp_int << " ";
    cout << "Enter mark of physics : ";
    cin >> temp_int;
    student.physics = temp_int;
    middle += temp_int;
    fout << temp_int << " ";
    cout << "Enter mark of math : ";
    cin >> temp_int;
    student.math = temp_int;
    middle += temp_int;
    fout << temp_int << " ";
    cout << "Enter mark of informatics : ";
    cin >> temp_int;
    student.informatics = temp_int;
    middle += temp_int;
    fout << temp_int << " ";
    cout << "Enter mark of chemistry : ";
    cin >> temp_int;
    student.chemistry = temp_int;
    middle += temp_int;
    fout << temp_int << " ";
    fout << middle / 4.;
    student.gap = temp_int;
    fout << endl;
    fout.close();
    push_back(students, student, quantity);
}

void show(const Student *students, int quantity)
{

    for (int i = 0; i < quantity; i++)
    {
        cout << "Name : " << students[i].name << endl;
        cout << "Surname : " << students[i].surname << endl;
        cout << "Patronymic : " << students[i].patronymic << endl;
        cout << "Group : " << students[i].number_group << endl;
        cout << "Year of birth : " << students[i].birthYear << endl;
        cout << "Physics : " << students[i].physics << endl;
        cout << "Math : " << students[i].math << endl;
        cout << "Informatics : " << students[i].informatics << endl;
        cout << "Chemistry : " << students[i].chemistry << endl;
        cout << "Middle mark : " << students[i].gap << endl;
    }

}
void individual(Student *students, int quantity)
{
    for (int i = 0; i < quantity; i++)
    {
        if (!isGood(students[i])) continue;
        cout << "Name : " << students[i].name << endl;
        cout << "Surname : " << students[i].surname << endl;
        cout << "Patronymic : " << students[i].patronymic << endl;
        cout << "Group : " << students[i].number_group << endl;
        cout << "Year of birth : " << students[i].birthYear << endl;
        cout << "Physics : " << students[i].physics << endl;
        cout << "Math : " << students[i].math << endl;
        cout << "Informatics : " << students[i].informatics << endl;
        cout << "Chemistry : " << students[i].chemistry << endl;
        cout << "Middle mark : " << students[i].gap << endl;
    }
}
void edit(Student *&students, int quantity) {
    system("cls");
    cout << "Vvedite nomer studenta korogo nuzhno izmenit: ";
    int number;
    cin >> number;
    cout << "Viberite chto vam nyzhno izmenit: " << endl;
    cout << "1 - Name" << endl;
    cout << "2 - Surname" << endl;
    cout << "3 - patronymic" << endl;
    cout << "4 - nember_group" << endl;
    cout << "5 - birthYear" << endl;
    cout << "6 - physics" << endl;
    cout << "7 - math" << endl;
    cout << "8 - informatics" << endl;
    cout << "9 - chemistry" << endl;
    int choice;
    cin >> choice;
    switch (choice)
    {
    case 1:
    {
        cout << "Vvedite imya: ";
        string nam;
        cin >> nam;
        students[number].name = nam;
    }
        break;
    case 2:
    {
        cout << "Vvedite famil: ";
        string nam;
        cin >> nam;
        students[number].surname = nam;
    }
        break;
    case 3:
    {
        cout << "Vvedite otchestv: ";
        string nam;
        cin >> nam;
        students[number].patronymic = nam;
    }
        break;
    case 4:
    {
        cout << "Vvedite nomer_group: ";
        int nam;
        cin >> nam;
        students[number].number_group = nam;
    }
        break;
    case 5:
    {
        cout << "Vvedite data rozhdeniya: ";
        int nam;
        cin >> nam;
        students[number].birthYear = nam;
    }
        break;
    case 6:
    {
        cout << "Vvedite ocenky po fizike: ";
        int nam;
        cin >> nam;
        students[number].physics = nam;
    }
        break;
    case 7:
    {
        cout << "Vvedite ocenky po mat: ";
        int nam;
        cin >> nam;
        students[number].math = nam;
    }
        break;
    case 8:
    {
        cout << "Vvedite ocenky po informat: ";
        int nam;
        cin >> nam;
        students[number].informatics = nam;
    }
        break;
    case 9:
    {
        cout << "Vvedite ocenky po himii: ";
        int nam;
        cin >> nam;
        students[number].chemistry = nam;
    }
        break;
    default:
        cout << "ERROR" << endl;
        break;
    }
    ofstream fout("File.txt", ios::out);
    for (int i = 0; i < quantity; i++) {
        fout << students[i].name << " ";
        fout << students[i].surname << " ";
        fout << students[i].patronymic << " ";
        fout << students[i].number_group << " ";
        fout << students[i].birthYear << " ";
        fout << students[i].physics << " ";
        fout << students[i].math << " ";
        fout << students[i].informatics << " ";
        fout << students[i].chemistry << " ";
        fout << students[i].gap << endl;
    }
    system("cls");
    cout << "Izmenino!!!" << endl;
}

int initiaize(Student *&students)
{
    int n = strCounter();
    students = new Student[n];
    ifstream fin("File.txt");
    string temp;
    int t;
    double tt;
    for (int i = 0; i < n; i++)
    {
        fin >> temp;
        students[i].name = temp;
        fin >> temp;
        students[i].surname = temp;
        fin >> temp;
        students[i].patronymic = temp;
        fin >> t;
        students[i].number_group = t;
        fin >> t;
        students[i].birthYear = t;
        fin >> t;
        students[i].physics = t;
        fin >> t;
        students[i].math = t;
        fin >> t;
        students[i].informatics = t;
        fin >> t;
        students[i].chemistry = t;
        fin >> tt;
        students[i].gap = t;
        temp = "";
        t = 0;
        tt = 0;
    }
    return n;
}

int main()
{
    Student *students;
    int quantity = initiaize(students);
    while (true)
    {
        system("cls");
        int choise = 0;
        menu();
        cin >> choise;
        switch (choise)
        {
        case 1: show(students, quantity); break;
        case 2: edit(students, quantity); break;
        case 3: add(students, quantity); break;
        case 4: individual(students, quantity); break;
        case 0: return 0;
        default:"ERROR!";
        }
        system("pause");
    }
}

void menu()
{
    cout << "Enter , what do you want :" << endl;
    cout << "1 - Show all data " << endl;
    cout << "2 - Edit " << endl;
    cout << "3 - Add " << endl;
    cout << "4 - Individual task " << endl;
    cout << "0 - Exit" << endl;
}