最新vc++程序设计

3.25设计一个类CRectangle,除了有相关的数据成员，该类要求包含下述成员1
函数：矩形从一个位置移动到另一个位置的Move（）函数；改变矩形大小的Size 2
（）函数；返回矩形左上角的坐标坐标值的Where（）函数；计算矩形面积的Area 3
（）函数。

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代码如下：#include <iostream.h>
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#include <stdlib.h>
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class CRectangle
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{
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private: double X;
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double Y;
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double Length;
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double Width;
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public:
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CRectangle(double s, double m, double L, double W)
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{
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X=s;
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Y=m;
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Length=L;
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Width=W;
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}
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~CRectangle()
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{}
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void Move(double , double);
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void Size(double ,double);
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void Where();
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void Area();
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};
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void CRectangle::Move(double x, double y)
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{
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cout<<"矩形按向量("<<x<<","<<y<<")移动"<<endl;
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cout<<"现在矩形左上角所在的位置:"<<endl;
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cout<<"("<<X+x<<","<<Y+y<<")"<<endl;
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}
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void CRectangle::Where()
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{
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cout<<"现在矩形左上角所在的位置:"<<endl;
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cout<<"("<<X<<","<<Y<<")"<<endl;
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}
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void CRectangle::Size(double l, double w) 39
{
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cout<<"要更改的长:"<<l<<endl;
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cout<<"要更改的宽:"<<w<<endl;
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Length=l;
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Width=w;
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cout<<"面积是："<<Length*Width<<endl;
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}
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void CRectangle::Area()
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{ double area;
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area=Length*Width;
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cout<<"面积是："<<area<<endl;
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}
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int main()
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{
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CRectangle cr(2,3,5,4);
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cr.Where();
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cr.Area();
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cr.Move(1,2);
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cr.Size(4,5);
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return 0;
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}
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运行结果如下:
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2.设计一个类
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#include<iostream>
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using namespace std;
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class CPetrol
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{
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public: CPetrol();
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void setamount();
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double total;
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private: double am_90;
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double am_93;
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double am_98;
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double price_90;
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double price_93;
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double price_98;
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};
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CPetrol::CPetrol()
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{
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price_90=3.96;
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price_93=4.05;
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price_98=4.38;
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}
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void CPetrol::setamount()
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{
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cout<<"input three amounts!"<<endl;
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cin>>am_90>>am_93>>am_98;
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total=am_90*price_90+am_93*price_93+am_98*price_98;
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}
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void main()
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{
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CPetrol c;
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c.setamount();
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cout<<"The total is"<<c.total<<endl;
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}
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运行结果如下:
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3.
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#include<iostream.h>
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class Line
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{
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friend void setpoint(Line &A,Line &B); 102
private: double a;
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double b;
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double c;
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public:
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Line (double a1, double b1, double c1) 107
{
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a=a1;
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b=b1;
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c=c1;
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}
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~Line(){};
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};
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void setpoint(Line &A,Line &B)
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{
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double x;
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if(A.a/B.a!=A.b/B.b)
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{
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x=-100; while(1)
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{
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if(( (-A.c-A.a*x)/A.b - (-B.c-B.a*x)/B.b ) < 0.00001) 122
break;
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x=x+0.00001;
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}
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cout<<x<<" "<<(-A.c-A.a*x)/A.b;
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}
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else
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cout<<"error"<<endl;
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}
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void main ()
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{
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Line A(1,2,-15),B(4,5,-16);
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setpoint(A,B);
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}
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