in c++, how do I change this into smart pointers?

#include #include #include #include using namespace std; class GradeRecord { public: GradeRecord(int id, double grade) : _studentId(id), _grade(grade) {} int getId() const { return _studentId; } void setGrade(double grade) { _grade = grade; } friend ostream& operator<<(ostream& out, const GradeRecord& record) { out << "RECORD: student #" << record._studentId << " grade = " << record._grade << endl; return out; } private: int _studentId; double _grade; }; class Gradebook { public: Gradebook() : _records() {} ~Gradebook() { } void addRecord(int studentId, double grade) { GradeRecord* newRecord = new GradeRecord(studentId, grade); _records.push_back(newRecord); } void updateRecord(int studentId, double grade) { GradeRecord* record = nullptr; for (int i = 0; i < _records.size(); ++i) { if (_records.at(i)->getId() == studentId) { record = _records.at(i); break; } } if (record != nullptr) { record->setGrade(grade); } } friend ostream& operator<<(ostream& out, const Gradebook& gradebook) { out << "GRADEBOOK contains " << gradebook._records.size() << "students" << endl; for (int i = 0; i < gradebook._records.size(); i++) out << "\t" << *gradebook._records.at(i); return out; } private: vector _records; }; int main() { Gradebook* grades = new Gradebook(); cout << *grades << endl; grades->addRecord(24, 3.1); grades->addRecord(129, 3.1); grades->addRecord(31, 3.1); grades->addRecord(44, 3.1); grades->addRecord(5, 3.1); cout << *grades << endl; grades->updateRecord(24, 4.0); grades->updateRecord(31, 4.0); cout << *grades << endl;

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