Гришин  Tmsu    2
Ардашев Tmsu    3
Котов   Smdf    4
Евсеев  Smdf    3
Новиков LLsd    2

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

using namespace std;

struct data_box
{
    char second_name[50];
    char subject_name[50];
    int subject_val;
};

int main()  {
    setlocale(LC_ALL, "Russian");

    struct data_box data_arr[4];


    char data_second_name[50], data_subject_name[50];
    int data_subject_val;

    int i,j = 0;

    std::ifstream data_file;
    std::string str;

    data_file.open("data.txt");

    while (data_file >> data_second_name >> data_subject_name >> data_subject_val) {

        strcpy(data_arr[j].second_name, data_second_name);
        strcpy(data_arr[j].subject_name, data_subject_name);

        data_arr[j].subject_val = data_subject_val;

        j++;
    }
    for (i = 0; i < (sizeof(data_arr)/sizeof(data_arr[0])); i++){
        cout << data_arr[i].second_name;
    }


    data_file.close();

    return 0;
}

ГришинАрдашевКотовЕвсеев
Process returned -1073741819 (0xC0000005)   execution time : 9.177 s
Press any key to continue.

#include <iostream>
#include <fstream>
#include <string>
#include <vector>

using namespace std;

struct data_box
{
    string second_name;
    string subject_name;
    int subject_val;
};

int main()
{
    setlocale(LC_ALL, "Russian");
    vector<data_box> data_arr;

    ifstream data_file("data.txt");
    if (!data_file.is_open()) exit(EXIT_FAILURE);

    data_box tmp;
    while(data_file >> tmp.second_name >> tmp.subject_name >> tmp.subject_val) {
        data_arr.push_back(tmp);
    }

    for (int i = 0; i < data_arr.size(); i++) cout << data_arr[i].second_name << endl;
    return 0;
}

int main()
{
    setlocale(LC_ALL, "Russian");
    vector<data_box> data_arr;

    ifstream data_file("data.txt");
    if (!data_file) exit(EXIT_FAILURE);

    data_box tmp;
    while(data_file >> tmp.second_name >> tmp.subject_name >> tmp.subject_val) {
        data_arr.push_back(move(tmp));
    }

    for (const auto &data: data_arr) cout << data.second_name << endl;
    return 0;
}