用C++的类和对象求三角形面积和周长 - 编程论坛

#2

peach54602013-03-20 15:53

哇...100分

晚上回去写...

[ 本帖最后由 peach5460 于 2013-3-20 15:55 编辑 ]

#3

yuccn2013-03-20 16:37

class CTriangle
{
public:
    CTriangle(double a,double b,double c)
    {
        m_a = a;
        m_b = b;
        m_c = c;
    };
    ~CTriangle(){};

    double GetArea()
    {
        if((m_a+m_b>m_c) && (m_a+m_c>m_b) && (m_b+m_c>m_a)){
            double s=(m_a+m_b+m_c)/2;
            return sqrt(s*(s-m_a)*(s-m_b)*(s-m_c));
        }
        else{
            return -1;
        }
    }
    double GetPerimeter()
    {
        if((m_a+m_b>m_c) && (m_a+m_c>m_b) && (m_b+m_c>m_a)){
            return m_a+m_b+m_c;
        }
        else{
            return -1;
        }
    }

protected:
    double m_a;
    double m_b;
    double m_c;
};

int main(void)
{
    double area,perimeter,s,a,b,c;
    printf("Enter a b c:");
    scanf("%lf%lf%lf",&a,&b,&c);
    CTriangle triangle(a,b,c);

    printf("area=%.2f,perimeter=%.2f\n", triangle.GetArea(),triangle.GetPerimeter());
    return 0;
}

#4

wp2319572013-03-20 16:40

强烈关注

#5

azzbcc2013-03-20 17:38

yu版手快些，我稍微蹭点就行

#6

qunxingw2013-03-20 19:38

支持各位

#7

gwcome2013-03-20 20:37

程序代码：

#include<iostream>
#include <math.h>
class Triangle
{
public:
     Triangle(double a,double b,double c);//构造函数
    bool Triangle_judge();//是否可以组成三角形
    double Triangle_area();//求面积
    double Triangle_perimeter();//求周长
private:
    double length_1;
    double length_2;
    double length_3;
};

Triangle::Triangle(double a,double b,double c)
{
    length_1=a;
    length_2=b;
    length_3=c;
}

bool Triangle::Triangle_judge()
{
    return ( (length_1+length_2>length_3) && (length_1+length_3>length_2) && (length_2+length_3>length_2) )?true:false;
}

double Triangle::Triangle_area()
{
    double s;
    s=(length_1+length_2+length_3)/2;
    return sqrt(s*(s-length_1)*(s-length_2)*(s-length_3));
}

double Triangle::Triangle_perimeter()
{
    return length_3+length_2+length_1;
}
int main()
{
    std::cout<<"请输入三角形的三个边长"<<'\n';
    double a,b,c;
    std::cin>>a>>b>>c;
    Triangle triangle(a,b,c);
    if (triangle.Triangle_judge())
    {
        std::cout<<"三角形的面积是"<<triangle.Triangle_area()<<'\n';
        std::cout<<"三角形的周长是"<<triangle.Triangle_perimeter()<<std::endl;

    }
    else
    {
        std::cout<<"你所输入的三个边不能构成三角形"<<'\n';
    }
    return 0;
}

#8

gwcome2013-03-20 20:43

判断是否能构成三角形的条件是(a+b>c)&&(a+c>b)&&(b+c>a)

#9

信箱有效2013-03-20 22:10

跟贴学习

#10

peach54602013-03-21 08:22

以下是引用yuccn在2013-3-20 16:37:35的发言：

class CTriangle
{
public:
    CTriangle(double a,double b,double c)
    {
        m_a = a;
        m_b = b;
        m_c = c;
    };
    ~CTriangle(){};

    double GetArea()
    {
        if((m_a+m_b>m_c) && (m_a+m_c>m_b) && (m_b+m_c>m_a)){
            double s=(m_a+m_b+m_c)/2;
            return sqrt(s*(s-m_a)*(s-m_b)*(s-m_c));
        }
        else{
            return -1;
        }
    }
    double GetPerimeter()
    {
        if((m_a+m_b>m_c) && (m_a+m_c>m_b) && (m_b+m_c>m_a)){
            return m_a+m_b+m_c;
        }
        else{
            return -1;
        }
    }

protected:
    double m_a;
    double m_b;
    double m_c;
};

int main(void)
{
    double area,perimeter,s,a,b,c;
    printf("Enter a b c:");
    scanf("%lf%lf%lf",&a,&b,&c);
    CTriangle triangle(a,b,c);

    printf("area=%.2f,perimeter=%.2f\n", triangle.GetArea(),triangle.GetPerimeter());
    return 0;
}

高手...
再提个抽象类出来,搞个继承...
基本上面向对象三大特性就齐活啦