7.2

#include <iostream>
#include <string>

const int size = 20;

struct study
{
    char name[20];
    int raiting_math;
    int raiting_phys;
    int raiting_prog;

};
using namespace std;
int main()
{
    const int size = 20;
    setlocale(LC_ALL, "rus");
    int n = 0;
    cout << "1 - мат. анализ\n2 - физика\n3 - программирование\n";
    cin >> n;
    int amount;
    cout << "amount = ";
    cin >> amount;
    cout << "\n";
    study* p_study = new study[amount];

    p_study[1] = { "Alexey", 6, 5, 7 };
    if (n > 1)
    {
        p_study[2] = { "Pavel", 5, 3, 7 };
    }
    if (n > 2)
    {
        p_study[3] = { "Ilya", 2, 6, 8 };
    }
    if (n > 3)
    {
        p_study[4] = { "Arthur", 7, 5, 9 };
    }
    if (n > 4)
    {
        p_study[5] = { "Lehan", 2, 3, 3 };
    }




    cout << "\nНеуспевающие студенты:\n";
    for (int i = 1; i < amount; i++)
    {

        if (n == 1)
        {
            if (p_study[i].raiting_math < 4)
            {
                cout << p_study[i].name << endl;
            }
        }
        if (n == 2)
        {
            if (p_study[i].raiting_phys < 4)
            {
                cout << p_study[i].name << endl;
            }
        }
        if (n == 3)
        {
            if (p_study[i].raiting_prog < 4)
            {
                cout << p_study[i].name << endl;
            }
        }

    }
    delete[]p_study;

    return 0;
}