题干给出一个类

class point{
    int x;
    int y;
public:
    void setxy(int a, int b){x=a;y=b;}
    int getx(){return x;}
    int gety(){return y;}
}

要求设计矩形类，该矩形类继承point类，属性有长宽和左上角坐标，并有以下功能：

1.可以由用户输入矩形的左上角坐标和长宽

2.可以显示矩形的诸属性

3.可以求得并输出该矩形的周长和面积

#include
using namespace std;

class Point {
public:
	int x;
	int y;
public:
	void setxy(int a, int b) {
		x = a;
		y = b;
	}
	int getx() {
		return x;
	}
	int gety() {
		return y;
	}
};

class Rectangle :public Point {
public:
	int width, length;
public:
	Rectangle() {
		int x, y;
		cout << "输入左上角坐标:";
		cin >> x >> y;
		setxy(x, y);
		cout << "输入宽度和长度:";
		cin >> width >> length;
		cout << "该矩形四个顶点的坐标为：" << "(" << x << "," << y << ")" << " "
			<< "(" << x + length << "," << y << ")" << " "
			<< "(" << x + length << "," << y - width << ")" << " "
			<< "(" << x << "," << y - width << ")" << " "< 
 
 
 
知识补充 
1.int main(int argc,char* argv[]) 
argc是命令行总的参数个数
 
argv[]是argc个参数，其中第0个参数是程序的全名，以后的参数是命令行后面跟的用户输入的参数
 
是main函数的最标准写法。