Page 78 problem 18

#include<bits/stdc++.h>

using namespace std;


#define Line cout << "--------------------------------------------------\n"
#define forn(i, n) for(int i = 0; i < int(n);i++)
const int INF = 1e9 + 13;
const int N = 1e5 + 13;
ifstream in("input.txt");
struct student{
    int group;
    string first_name, second_name, third_name;
    int birth_year;
    int marks[5];
    void print();

};
void student::print(){
        Line;
        cout << "Full name: " << first_name << ' ' << second_name << ' ' << third_name << "\nbirth year: " << birth_year <<
            "\n" << "marks: " << marks[0] << ' ' << marks[1] << ' ' << marks[2] << ' ' << marks[3] << ' ' << marks[4] << endl;
}
bool check(student a, student b){
    if (a.first_name < b.first_name)
        return true;
    else
        if (a.second_name < b.second_name && a.first_name == b.first_name)
            return true;
        else
            if (a.third_name < b.third_name && a.second_name == b.second_name)
                return true;

    return false;
}
void MySort(student* a, int n){
    forn(i, n){
        student Min = a[i];
        int idx = i;
        for (int j = i + 1; j < n; ++j)
            {
                if (check(a[j], a[idx]))
                {
                    Min = a[j];
                    idx = j;
                }
            }
        swap(a[i], a[idx]);
    }
}
student get_student(){
    student res;
    in >> res.group;
    in >> res.first_name >> res.second_name >> res.third_name;
    in >> res.birth_year;
    forn(i, 5)
        in >> res.marks[i];
    return res;
}
  student a[N];
int main(){

    int n = 0;

    while (in.peek() != EOF)
    {
        a[n] = get_student();
        if (a[n].first_name == "")
            n--;
        n++;
    }
    MySort(a, n);
    forn(i, n)
        a[i].print();
}