3-4 计算长方形的周长和面积

题目描述

输入

输出

示例输入

56 32

示例输出

the length and width of r1 is:56,32
the perimeter of r1 is:176
the area of r1 is:1792
the length and width of r2 is:56,32
the perimeter of r2 is:176
the area of r2 is:1792

提示

来源

示例程序

#include <iostream>

using namespace std;

class Rect
{
private:
    double l;
    double w;

public:
    Rect (double x=0,double y=0);
    Rect (const Rect &a);

    const void display1()
    {
        cout<<"the length and width of r1 is:"<<l<<","<<w<<endl;
        cout<<"the perimeter of r1 is:"<<(l+w)*2<<endl;
        cout<<"the area of r1 is:"<<l*w<<endl;
    }

    const void display2()
    {
        cout<<"the length and width of r2 is:"<<l<<","<<w<<endl;
        cout<<"the perimeter of r2 is:"<<(l+w)*2<<endl;
        cout<<"the area of r2 is:"<<l*w<<endl;
    }
};

Rect::Rect(double x,double y)
{
    l=x;
    w=y;
}

Rect::Rect(const Rect & a)
{
    l=a.l;
    w=a.w;
}

int main()
{
    double x,y;
    cin>>x>>y;
    if(x<0|| y<0)
    {
        x=0;
        y=0;
    }
    Rect rect(x,y);
    Rect rect_copy=rect;

    rect.display1();
    rect_copy.display2();
    return 0;
}

3-4 计算长方形的周长和面积

原文：http://blog.csdn.net/u013634961/article/details/39925757