#include <iostream>
#include <cmath>  // Needed for M_PI and pow()
using namespace std;

double volume_of_sphere( double r )
{
    return( 4.0 * M_PI * pow( r, 3 ) / 3.0 );
}

int main()
{
    double radius, volume;
    
// cout.precision() is used to set the number of significant
// digits that are displayed    
    cout.precision( 10 );  
    
    cout << "Enter the radius of your sphere: ";
    cin >> radius;
    volume = volume_of_sphere( radius );
    cout << "\nThe volume of your sphere is " << volume << endl;
    
    cout << "\n\n"; system( "PAUSE" );
    return( 0 );
}