编程日记13

题目1

【问题描述】

根据点的类构造线和三角形类，并测试

//根据点的定义，写出线段和三角形的定义，并通过主程序进行验证
//mypoint.h
class  myPoint
{
public:
        myPoint();
        myPoint(double  x,  double  y);
        double  getX();
        double  getY();
private:
        double  mX,mY;
};

//此区域编写

int  main()
{
        double  x1,  x2,  x3,  y1,  y2,  y3;
        cout  <<  "请输入点1的x的值：";
        cin  >>  x1;
        cout  <<  "请输入点1的y的值：";
        cin  >>  y1;
        cout  <<  "请输入点2的x的值：";
        cin  >>  x2;
        cout  <<  "请输入点2的y的值：";
        cin  >>  y2;
        cout  <<  "请输入点3的x的值：";
        cin  >>  x3;
        cout  <<  "请输入点3的y的值：";
        cin  >>  y3;
        cout  <<  "点1的坐标为：("  <<  x1  <<  ","  <<  y1  <<  ")"  <<  endl;
        cout  <<  "点2的坐标为：("  <<  x2  <<  ","  <<  y2  <<  ")"  <<  endl;
        cout  <<  "点3的坐标为：("  <<  x3  <<  ","  <<  y3  <<  ")"  <<  endl;
        myPoint  p1(x1,  y1),  p2(x2,  y2),  p3(x3,  y3);
        Line    line1(p1,p2);
        cout<<"线长度:"<<line1.GetDistance()<<endl;
        Triangle  t(p1,  p2,  p3);
        cout  <<  "该三角形的周长为："  <<  t.getGirth()  <<  endl;
        cout  <<  "该三角形的面积为："  <<  t.getArea()  <<  endl;
        return  0;
}

【代码】

#include<iostream>
#include<cmath>//包含sqrt的头文件
using namespace std;
myPoint::myPoint(double x,double y)//函数实现
{mX=x;
    mY=y;
}
myPoint::myPoint()
{mX=0;
    mY=0;
}
double myPoint::getX()
{return mX;}
double myPoint::getY()
{return mY;}
class Line//线类
{myPoint x;//定义2个点
    myPoint y;
public:
    Line(myPoint b,myPoint k):x(b),y(k)//初始化
    {
    }
    double GetDistance()//计算线段长度的函数
    {double b;
        b=sqrt((x.getX()-y.getX())*(x.getX()-y.getX())+((x.getY()-y.getY())*(x.getY()-y.getY())));
        return b;
    }};
    class Triangle//三角类
    {myPoint x,y,z;//定义3个点
    public:
        Triangle(myPoint h,myPoint s,myPoint a):x(h),y(s),z(a)//初始化
        {
        }
        double getGirth()//计算三角形周长的函数
        {Line a(x,y);//定义三条线段
            Line b(y,z);
            Line c(x,z);
            double C;
            C=a.GetDistance()+b.GetDistance()+c.GetDistance();//调用线类的函数
            return C;
        }
        double getArea()//海伦公式=√[p(p-a)(p-b)(p-c)]，计算三角形面积的函数
        {Line a(x,y);//定义三条线段
            Line b(y,z);
            Line c(x,z);
            double p;
            p=(this->getGirth())/2;
            double f;
            f=sqrt(p*(p-a.GetDistance())*(p-b.GetDistance())*(p-c.GetDistance()));//海伦公式计算三角形面积
            return f;
        }
    };

题目2

【问题描述】

编写类描述如下图形并求出阴影（蓝色）部分的面积
圆形正方形组合图形

【输入形式】

输入圆半径:2

输入正方形边长:3

【输出形式】

圆面积为：12.56

正方形面积为：9

组合面积为：3.56

#include<iostream>
using  namespace  std;
const  double  PI=3.14;
class  Circle  {

//此区域编写

};
class  Square  {

//此区域编写

};

//此区域编写

int  main()
{
double  r,  len;Circle  *pc;Square  *ps;
cout  <<  "输入圆半径:";
cin  >>  r;
Circle  r1(r);
cout  <<  "输入正方形边长:";
cin  >>  len;
Square  s1(len);
Mix  m1(r,  len);
pc=&r1;
cout<<"圆面积为："<<pc->getArea()<<endl;
ps=&s1;
cout<<"正方形面积为："<<ps->getArea()<<endl;
//pc=&m1;
cout<<"组合面积为："<<m1.getArea()<<endl;
return  0;
}

【代码】

private:
       int r;
   public:
       Circle(){}
       Circle(int r)
       {
            this->r=r;
       }
      double getArea()
       {
           return PI*r*r;
       }

private:
       int x;
   public:
       Square(){}
       Square(int x)
       {
         this->x=x;
       }
       double getArea()
       {
           return x*x;
       }

class  Mix
{
 private:
        Square b;//会用到默认无参构造函数
        Circle c;
    public:
        Mix(Circle C,Square B)
        {
            b=B,c=C;
        }
        void set(Circle C,Square B)
        {
            c=C,b=B;
        }
        double getArea()
        {
            return c.getArea()-b.getArea();            
        }

};