Массив "Студенты". Выведите на экран дисциплину, которую не желают изучать большинство студентов

#include <iostream>
#include <string>
#include <vector>
#include <exception>
#include <algorithm>
 
class invalid_initializer_list : public std::exception {
public:
    virtual const char* what () const noexcept {
        return "Initialzier list must have 5 members";
    }
};
 
std::string disciplines[] = { "Physics", "Computer science", "Mathematics", "Operational research", "General engineering" };
 
struct Student {
    std::string surname, faculty;
    int group;
    int chase[5]; // Раз уж символ 1 или 0, хотя я бы сделал bool...
    int average_score;
    Student(std::string s, std::string f, int g, const std::initializer_list<int>& c, int a) :
    surname(s), faculty(f), group(g), average_score(a) {
        if (c.size() != 5) throw invalid_initializer_list();
        std::copy(c.begin(), c.end(), chase);
    }
};
 
template<size_t SIZE>
std::string disciplines_to_s(const int (&arr)[SIZE]){
    std::string acc;
    int n = 0;
    std::for_each(std::begin(arr), std::end(arr), [&acc, &n] (int a) {
        if (a) {
            if (n) acc += ", ";
            acc += disciplines[n];
        }
        ++n;
    });
    return acc;
}
 
std::ostream& operator << (std::ostream& str, const Student& s) {
    return str <<
        "Surname: " << s.surname <<
        ", facluty: " << s.faculty <<
        ", group: " << s.group <<
        ", average score: " << s.average_score <<
        ", chosen disciplines: " << disciplines_to_s(s.chase) << std::endl;
}
 
int main ( ) {
    Student arr[] = {
        Student("Pupkin", "Maths and computer science", 101, { 0, 1, 1, 0, 0 }, 240),
        Student("Vasechkin", "Aerospace engineering", 201,   { 1, 1, 1, 0, 1 }, 260),
        Student("Morozov", "Civil engineering", 204,         { 1, 0, 1, 1, 1 }, 250)
    };
    
    std::sort(std::begin(arr), std::end(arr), [ ] (Student& a, Student& b) -> bool {
        return a.average_score > b.average_score;
    });
    
    std::for_each(std::begin(arr), std::end(arr), [ ] (Student& a) { 
        std::cout << a; 
    });
    
    std::pair<int, int> popularity[5];
    int n = 0;
    std::generate(std::begin(popularity), std::end(popularity), [&n, &arr] () -> std::pair<int, int> {
        int t = std::count_if(std::begin(arr), std::end(arr), [&n] (Student& ref) -> bool {
            return ref.chase[n];
        });
        ++n;
        return std::pair<int, int>(n - 1, t);
    });
    
    
    std::sort(std::begin(popularity), std::end(popularity), [ ] (std::pair<int, int>& a, std::pair<int, int>& b) -> bool {
        return a.second < b.second;
    });
    
    std::cout << "\nThe least popualar discipline: " << disciplines[popularity[0].first] << std::endl;
    
    return 0;
}