Soc, prva vjezba

#include <vector>
#include <iostream>
#include <algorithm>
#include <fstream>
// nisam ukljucio using namespace std, a string se nalazi u std namespace, pa moram ispred string pisati std ::

class Student
{
    private:
       std::string name;
       int points, index;

    public:
       Student(const std :: string& name = "", const int points = 0, const int index = 0) :
        name(name), points(points), index(index) {} //konstruktor sa podrazumijevanim parametrima, zamjena za prazan i sa parametrima
                                                    //inace bi morali praviti posebno prazan, a posebno sa parametrima
                                                    //ovako jednim udarcem dvije muve
       std::string get_name() const {return name;}
       int get_points() const {return points;}
       int get_index() const {return index;}

       void set_name(const std::string& name) {this->name = name;} //ako hocemo ista imena da koristimo, moramo preko this pokazivaca
       void set_points(const int points) {this->points = points;}
       void set_index(const int index) {this->index = index;}

       friend bool operator < (const Student& s1, const Student& s2)  //prijateljska funkcija, moze koristiti polja iz private
       {       //prototip funkcije mora biti u publicu, a tijelo moze a ne mora biti unutra, moze i van...
        if(s1.points != s2.points)
        {
          return s1.points < s2.points;   //praksa je da ako su funkcije inline, tijelo bude zajedno sa prototipom, a ako su duz van..
        }
        else
        {
            return s1.index < s2.index;
        }
       }

      friend std::ostream& operator << (std::ostream& out, const Student& s)
      {
        out << s.name << ": points=" << s.points << ", index=" << s.index;
        return out;
      }

};

void print_list(std::vector<Student>& lst)
{
    std::vector<Student>::iterator it;

    for(it = lst.begin(); it != lst.end(); ++it)
        std::cout << *it << std::endl;
    std::cout << std::endl;
}

void scan_infile(std::vector<Student>& lst)
{
    std::string name;
    int points, index;
    std::ifstream infile;
    infile.open("students.txt");
    if (infile.is_open())
        while(!infile.eof())
        {
            infile >> name >> points >> index;
            lst.push_back(Student(name,points,index));
        }
}

int main()
{
    std::vector<Student> st;

    scan_infile(st);

    print_list(st);

    std::sort(st.begin(), st.end());
    print_list(st);

    return 0;
}