第二学期第三周 项目1

/*一点思考：因为主函数的限制，这个程序并没有验证三边，在不满足构成三角形的条件下终止程序的功能，如果想有此功能则需要在主函数中加判断*/#include <iostream>#include <cmath>using namespace std;class Triangle{public:    void setABC(double x,double y,double z);//    void getABC(double *x,double *y,double *z);    double perimeter(void);    double area(void);private:    double a,b,c;};int main(){    Triangle tri1;    tri1.setABC(4,5,6);    double x,y,z;    tri1.getABC(&x,&y,&z);    cout<<"三边为"<<x<<'\t'<<y<<'\t'<<z<<endl;    cout<<"三角形的周长为"<<tri1.perimeter()<<'\t'<<"面积为"<<tri1.area()<<endl;    return 0;}void Triangle::setABC(double x,double y,double z){    if(x+y>z&&y+z>x&&x+z>y)    {        a=x;        b=y;        c=z;    }    else        cout<<"不能构成三角形";}void Triangle::getABC(double *x,double *y,double *z){    *x=a;    *y=b;    *z=c;}double Triangle::perimeter(void){    return a+b+c;}double Triangle::area(void){    double p=(a+b+c)/2;    return sqrt(p*(p-a)*(p-b)*(p-c));}

运行结果：

#include <iostream>#include <cmath>using namespace std;class Triangle{   public:    void setA(double x)    {        a=x;    };    void setB(double y)    {        b=y;    };    void setC(double z)    {        c=z;    };    double getA()    {        return a;    }    double getB()    {        return b;    }    double getC()    {        return c;    }    bool isTriangle();//用于判断能否构成三角形    double perimeter(void);    double area(void);private:    double a,b,c; //三边为私有成员数据};int main(){    Triangle tri1;//定义三角形类的一个实例（对象）    double x,y,z;    cout<<"请输入三角形的三边：";    cin>>x>>y>>z;    tri1.setA(x);    tri1.setB(y);    tri1.setC(z);//为三边置初值    if(tri1.isTriangle())    {        cout<<"三条边为："<<tri1.getA()<<','<<tri1.getB()<<','<<tri1.getC()<<endl;        cout<<"三角形的周长为："<< tri1.perimeter()<<'\t'<<"面积为："<< tri1.area()<<endl;    }    else        cout<<"不能构成三角形"<<endl;    return 0;}    bool Triangle::isTriangle(){    return (a+b>c&&a+c>b&&b+c>a);}double Triangle::perimeter(){    return a+b+c;}double Triangle::area(){    double p=(a+b+c)/2;    return sqrt(p*(p-a)*(p-b)*(p-c));}

运行结果：