#include <iostream>
using namespace std;
class Point
{
public:
  Point(int x = 0, int y = 0):x_(x), y_(y){}
  int X()const{return x_;}
  int Y()const{return y_;}
  void X(int x){ x_ = x; }
  void Y(int y){ y_ = y; }
private:
  int x_;
  int y_;
};

class Rectangle
{
public:
  Rectangle(Point l, Point r) :ld(l), ru(r){}
  int Area(){ return (ru.x - ld.x) * (ru.y - ld.y);
  void Coord(){
    cout<<"Point 1: "<<ld.x<<","<<ld.y<<endl;
    cout<<"Point 2: "<<ru.x<<","<<rd.y<<endl;
    cout<<"Point 3: "<<ru.x<<","<<ru.y<<endl;
    cout<<"Point 1: "<<ld.x<<","<<ru.y<<endl;
  
  }
private:
  Point ld; //左下角的点
  Point ru; //右上角的点
};

int main()
{
  Point one(1, 1), two(10,10);
  Rectangle r(one, two);
  cout<<r.Area()<<endl;
  r.Coord();
  return 0;
}

#include <iostream>
using namespace std;
class Point
{
public:
  Point(int x = 0, int y = 0):x_(x), y_(y){}
  int X()const{return x_;}
  int Y()const{return y_;}
  void X(int x){ x_ = x; }
  void Y(int y){ y_ = y; }
private:
  int x_;
  int y_;
};

class Rectangle
{
public:
  Rectangle(Point l, Point r) :ld(l), ru(r){}
  int Area(){ return (ru.x - ld.x) * (ru.y - ld.y); // 这行你漏了一个右括号了
  void Coord(){
    cout<<"Point 1: "<<ld.x<<","<<ld.y<<endl;
    cout<<"Point 2: "<<ru.x<<","<<rd.y<<endl;     rd是什么？有这个对象吗？
    cout<<"Point 3: "<<ru.x<<","<<ru.y<<endl;     注意这个红快和上面的那行红快，x，y 这两个变量，ru 和ld 有这个成员吗？那边是x_ 和y_。
                                                  同时，那边权限是private:的。你明白private: 和public的差别不？
    cout<<"Point 1: "<<ld.x<<","<<ru.y<<endl;
  
  }
private:
  Point ld; //左下角的点
  Point ru; //右上角的点
};

int main()
{
  Point one(1, 1), two(10,10);
  Rectangle r(one, two);
  cout<<r.Area()<<endl;
  r.Coord();
  return 0;
}

楼上正解，，顶

这哥们结贴有意思~