[C++] Has-a 관계로 구현한 성적관리프로그램

#include <iostream>
#include <string>
#include <iomanip>
using namespace std;
 
class Name {
    string name;
public:
    Name() { this->name = "noName"; }
    Name(string name) { this->name = name; }
    void setName(string name) { this->name = name; }
    string getName() const { return name; }
};
 
class Subject {
    int subj;
public:
    Subject(int subj = 0) { this->subj = subj; }
    void setSubj(int subj) { this->subj = subj; }
    int getSubj() const { return subj; }
};
 
class ScoMag {
    Name name;
    Subject kor, eng, math;
    float avg;
public:
    ScoMag() { }
    ScoMag(string name, Subject subj) : name(name) { }
 
    // setter
    void setName(string name) { this->name.setName(name); }
    void setKor(int kor) { this->kor.setSubj(kor); }
    void setEng(int eng) { this->eng.setSubj(eng); }
    void setMath(int math) { this->math.setSubj(math); }
 
    // getter
    string getName() const { return name.getName(); }
    int getKor() const { return kor.getSubj(); }
    int getEng() const { return eng.getSubj(); }
    int getMath() const { return math.getSubj(); }
 
    // total과 average는 set할 필요가 없으므로 getter만 만듦
    int getTotal() const {
        return kor.getSubj() + eng.getSubj() + math.getSubj();
    }
    float getAvg() const {
        return this->getTotal() / 3.f;
    }
};
 
void main()
{
    ScoMag *sm;
    string name;
    int score, total;
    float avg;
    int cnt;
 
    cout << "몇 명 성적 입력? : ";
    cin >> cnt;
    cout << cnt << "사람 만큼 성적 입력을 시작합니다." << endl;
    sm = new ScoMag[cnt];
 
    // 입력
    for (int i = 0; i < cnt; i++) {
        cout << "이름을 입력하세요. : ";
        cin >> name;
        sm[i].setName(name);
 
        cout << "국어 성적을 입력하세요 : ";
        cin >> score;
        sm[i].setKor(score);
 
        cout << "영어 성적을 입력하세요 : ";
        cin >> score;
        sm[i].setEng(score);
 
        cout << "수학 성적을 입력하세요 : ";
        cin >> score;
        sm[i].setMath(score);
    }
 
    // 출력
    for (int i = 0; i < cnt; i++) {
        // Fair style
        cout << "NAME" << setw(9)
             << "KOR" << setw(9)
             << "ENG" << setw(9)
             << "MATH" << setw(9)
             << "TOTAL" << setw(9)
             << "AVG" << endl;
 
        // CoRock sytle
        cout <<
            sm[i].getName() << setw(7) <<
            sm[i].getKor() << setw(9) <<
            sm[i].getEng() << setw(9) <<
            sm[i].getMath() << setw(9) <<
            sm[i].getTotal() << setw(13) <<
            sm[i].getAvg() << endl;
    }
 
    delete[]sm;
}

OOP는 확장성이 좋아야한다

국영수를 '사용'해라