example.cpp

#include "grade_school.h"

namespace grade_school {
void school::add(std::string const& name, int grade) {
    // Check if the student already exists
    if (students_.find(name) != students_.end()) {
        // Student already exists; do not add
        return;
    }
    // Add the student to the set of students
    students_.insert(name);
    // Proceed to add the student to the given grade in sorted order
    std::vector<std::string>& grade_roster = roster_[grade];
    auto it = lower_bound(grade_roster.begin(), grade_roster.end(), name);
    grade_roster.insert(it, name);
}

std::vector<std::string> school::grade(int grade) const {
    auto it = roster_.find(grade);
    return (it != roster_.end()) ? it->second : std::vector<std::string>{};
}

}  // namespace grade_school