pex3_3.cpp

来自「数据结构C++代码,经典代码,受益多多,希望大家多多支持」· C++ 代码 · 共 79 行

#include <iostream.h>

const float PI = 3.14159265;

// declare Circle class with data and method declarations
class Circle
{
    private:
        // data member radius is a floating point number
        float   radius;
        
    public:
        // constructor                
        Circle(float r);
        
        // measurement functions
        float Circumference(void) const;
        float Area(void) const;
        float SectorArea(float theta) const;
};

// class implementation

// constructor initializes the radius data member
Circle::Circle(float r): radius(r)
{ }

// return circumference
float Circle::Circumference() const
{
    return 2 * PI * radius;
}
        
// return area 
float Circle::Area() const
{
    return PI * radius * radius;
}

// return area 
float Circle::SectorArea(float theta) const
{
    return (theta/360) * PI * radius * radius;
}

void main ()
{
    float radius, numberRolls;
    float fenceCost, lawnCost, lawnArea; 

    // set fixed point output with 2 decimal places
    cout.setf(ios::fixed);
    cout.setf(ios::showpoint);
    cout.precision(2);
    
    // prompt for and input radius
    cout << "Enter the radius of the playground: ";
    cin >> radius;

    // declare the Circle objects
    Circle playground(radius);
     
    // Compute the cost of the Fence and output its value
    fenceCost = playground.Circumference() * 2.40;
    cout << "Fencing Cost is $" << fenceCost << endl;
    
	lawnArea = playground.Area() - playground.SectorArea(30);
	numberRolls = lawnArea / 16;
	lawnCost  = numberRolls * 4.00;
	cout << "Lawn Cost is $" << lawnCost << endl;
}

/*
<Run>
Enter the radius of the playground: 100
Fencing Cost is $1507.96
Lawn Cost is $7199.48
*/