Polygon 연습문제

#include <iostream>
#define _CRT_SECURE_NO_WARNINGS
#pragma warning(disable:4996)
#include <string>
 
using namespace std;
 
struct Point {
 
    //변수의 크기가 작거나 자주할당되는 객체는 구조체가 좋음
    int x, y;
};
 
class Polygon {
private:
    int nPoints;
    Point* points;
 
public:
    Polygon() {
        nPoints = 0;
        points = NULL;
    }
    Polygon(const int nPoints, const Point* points) :nPoints(nPoints) {
        this->points = new Point[nPoints];
        for (int i = 0; i < nPoints; i++) {
            this->points[i] = points[i];
        }
    }
 
    //복사 생성자
    Polygon(const Polygon& rhs) {
 
        nPoints = rhs.nPoints;
        points = new Point[nPoints];
 
        for (int i = 0; i < nPoints; i++) {
            points[i] = rhs.points[i]; //points는 구조체임 
            //구조체 내의 x,y는 포인터가 아니여서 깊은복사됨
        }
        cout << "깊은복사" << endl;
        
        
    }
 
 
    //이동 생성자
 
    Polygon(Polygon&& rhs) {
        nPoints = rhs.nPoints;
        points = rhs.points;
 
        //원본객체가 가리키는거 끊어줘야
        rhs.points = NULL;
 
        cout << "얕은복사" << endl;
    }
    ~Polygon() {
        delete[] points;
    }
 
    //복사 대입연산자
 
    Polygon& operator=(const Polygon& rhs) {
 
        if (this != &rhs) {
            delete[]points; // points에할당되어 있는거 미리 제거해줘야함.
            nPoints = rhs.nPoints;
            points = new Point[nPoints+ 1];
            for (int i = 0; i < nPoints; i++) {
                points[i] = rhs.points[i];
            }
        }
 
        cout << "깊은복사" << endl;
 
        return *this;
    }
 
    //이동 대입연산자 구현
 
    Polygon &operator=(Polygon&& rhs) {
        //자기 자신 대입하는거 막기 위함.
        if (this != &rhs) {
            nPoints = rhs.nPoints;
            delete[] points; //자기 자신 대입한거 있다면 버리고 
            points = rhs.points;//얕은복사
            rhs.points = NULL;//얕은복사하는 대신 연결을 끊어주기
 
            cout << "얕은복사" << endl;
            return *this;
        }
 
    }
    
    int getNPoints() const {
        return nPoints;
    }
 
    Point* getPoints() const {
        if (nPoints == 0) {
            return NULL;
        }
        return points;
    }
 
 
};
 
Polygon getSquare() {
    Point points[4] = { {0,0},{1,0},{1,1},{0,1} };
    Polygon p(4, points);
    return p;
}
 
int main() {
 
    Polygon a;
    a = getSquare();//얕은 복사 2회
    Polygon b = a;//깊은 복사 1회
    Polygon c;
    c = a;//깊은복사 1회
 
    int nPoints = c.getNPoints();
    Point* points = c.getPoints();
    for (int i = 0; i < nPoints; i++) {
        cout << "(" << points[i].x << "," << points[i].y << ")" << endl;
    }
}