АПОЖ

#include <cstring>
#include <iostream>
#include <fstream>

using namespace std;

class MyException{
public:
    MyException() : message("Mark must be between 0 and 10\n") {}
    void printMessage() { cout << message; }
private:
    const char * message;
};

class Man {
protected:
    char * name;
public:
    Man(char *);
    virtual ~Man();
    const char * getname() const;
};

Man :: Man(char * s) {
    int n = strlen(s);
    name = new char [n + 1];
    for (int i = 0; i <= n; ++i) name[i] = s[i];
}

Man :: ~Man() {
    delete [] name;
}

const char * Man :: getname() const {
    return name;
}

class Staff : public Man {
protected:
    char * disc;
public:
    Staff(char *, char *);
    virtual ~Staff();
    const char * getdisc() const;
};

Staff :: Staff(char * s, char * f) : Man(s) {
    int n = strlen(f);
    disc = new char [n + 1];
    for (int i = 0; i <= n; ++i) disc[i] = f[i];
}

Staff :: ~Staff() {
    delete [] disc;
}

const char * Staff :: getdisc() const {
    return disc;
}

class Student : public Staff {
private:
    struct MyStruct {
        char * disc;
        int mark;
    } my;
public:
    Student(char *, char *, int);
    virtual ~Student() {}
    int getmark() const;
};

Student :: Student(char * s, char * f, int x) : Staff(s, f) {
    if (x < 0 || x > 10) throw MyException();
    my.disc = disc;
    my.mark = x;
}

int Student :: getmark() const {
    return my.mark;
}

int main() {
    setlocale(LC_ALL, ".1251");
    ifstream fin("input.txt");
    int n, m;
    fin >> n;
    if (n <= 0) {
        cout << "Количество студентов должно быть положительным числом\n";
        return 0;
    }
    Student ** students = new Student * [n];
    for (int i = 0; i < n; ++i) {
        char * name, * disc;
        int mark;
        name = new char[20];
        disc = new char[20];
        fin >> name >> disc >> mark;
        try {
            students[i] = new Student(name, disc, mark);
        } catch (MyException e) {
            e.printMessage();
            students[i] = NULL;
        }
        delete [] name;
        delete [] disc;
    }

    char s[100];
    int ans = 0;
    cout << "Введите название дисциплины:\n";
    cin >> s;
    for (int i = 0; i < n; ++i)
        if (students[i] != NULL && strcmp(students[i] -> getdisc(), s) == 0) ans += students[i] -> getmark() > 3;
    cout << "Количество студентов, сдавших указанную дисциплину положительно: " << ans << endl << endl;

    fin >> m;
    Staff ** staffs = new Staff *[m];

    for (int i = 0; i < m; ++i) {
        char * name, * disc;
        name = new char[100];
        disc = new char[100];
        fin >> name >> disc;
        staffs[i] = new Staff(name, disc);
        delete [] name;
        delete [] disc;
    }

    for (int i = 0; i < m; ++i) {
        int sum = 0, count = 0;
        for (int j = 0; j < n; ++j)
            if (students[j] != NULL && strcmp(students[j] -> getdisc(), staffs[i] -> getdisc()) == 0) {
                ++count;
                sum += students[j] -> getmark();
            }
        cout << "Преподаватель: " << staffs[i] -> getname() << "\nДисциплина: " << staffs[i] -> getdisc();
        if (count) cout << "\nСредний балл: " << (sum + .0) / count;
        else cout << "Ни один студент не сдавал экзамен этому преподавателю";
        cout << endl << endl;
    }
    return 0;
}