Экзамен по информатике. Сведения об учениках

#include <iostream>
#include <fstream>
#include <map>
#include <utility>
#include <string>
#include <cstddef>
 
typedef std::pair<int, bool> int_bool_pair;
typedef std::map<int, int_bool_pair> int_pair_map;
 
int main()
{
    std::ifstream ifs("input.txt");
    if (!ifs)
    {
        std::cerr << "Unable to open file\n";
        return 1;
    }
    std::cin.rdbuf(ifs.rdbuf());
    int_pair_map maxSchoolMarks;
    std::string trash;
    int schoolNumber, mark;
    
    while(std::cin >> trash >> trash >> schoolNumber >> mark)
    {
        if (!maxSchoolMarks.count(schoolNumber))
            maxSchoolMarks.insert(std::make_pair
                (schoolNumber, std::make_pair(mark, false)));
            
        else if (maxSchoolMarks[schoolNumber].first < mark)
        {
            maxSchoolMarks[schoolNumber].first = mark;
            maxSchoolMarks[schoolNumber].second = false;
        }
        else if (maxSchoolMarks[schoolNumber].first == mark)
            maxSchoolMarks[schoolNumber].second = true;
    }
    
    std::size_t counter = 0;
    int maxMark = 0;
    for (auto &p : maxSchoolMarks)
        if (p.second.second)
        {
            std::cout << p.first << " ";
            counter++;
            maxMark = p.second.first;
        }
            
    if (counter == 1)
        std::cout << "\nMax mark = " << maxMark;
    else if (counter == 0)
        std::cout << "No such schools";
    std::cout << std::endl;
}