C++设计并测试一个名为Rectangle的矩形类，其属性为矩形的左下角与右下角两个点的坐标，根据坐标计算矩形的面积

#include<iostream>

using namespace std;

class Rectangle{

public:

    int j;
void area(int X=0,int Y=0,int A=0,int B=0);

private:
int x,y,a,b;

};

void Rectangle::area(int X,int Y,int A,int B){
x=X;y=Y;a=A;b=B;
j=(a-x)*(b-y);

 }

 int main(){
int x,y,a,b;
Rectangle rectangle;
cout<<"输入左下角坐标x和y"<<endl;
cin>>x>>y;
cout<<"输入右上角坐标为a和b"<<endl;
cin>>a>>b;

     rectangle.area(x,y,a,b);
cout<<"该矩形面积为："<<rectangle.j<<endl;
return 0;

 }