oj练习2

#include <iostream>using namespace std;class Rectangle{public:    Rectangle(double xx1=0,double yy1=0,double xx2=0,double yy2=0):x1(xx1),y1(yy1),x2(xx2),y2(yy2){};    void input();    Rectangle operator+(Rectangle&);    friend ostream&operator<<(ostream&,Rectangle&);private:    double x1，y1,x2,y2;   Rectangle Rectangle::operator+(Rectangle &c2){    return Rectangle(x1+c2.x1,y1+c2.y1,x2+c2.x2,y2+c2.y2);}ostream&operator<<(ostream&output,Rectangle &c2){    double s;    s=(c2.x2-c2.x1)*(c2.y2-c2.y1);    output<<s;    return output;}void Rectangle::input(){    cin>>x1>>y1>>x2>>y2;}int main(){    Rectangle p1(1,1,6,3),p2,p3;    p2.input();    p3=p1+p2;    cout<<p3;    return 0;}