#include <iostream>
using namespace std;
const double pi=3.1415;
float c(float r)
{
return 2.0*pi*r;
}
float s(float r)
{
return pi*r*r;
}
float v(float r)
{
return 4.0*r*r*r*pi/3.0;
}
float V(float r,float h)
{
return pi*r*r*h;
}
void main()
{
float r,h;
char m;
cout<<"请输入要计算的项目:圆面积(s);圆周长(c);圆球体积(v);圆柱体积(V):";
cin>>m;
switch(m)
{
case 's':cout<<endl<<"请输入圆半径r:";
cin>>r;
cout<<endl<<"圆的面积为"<<s(r);
break;
case 'c':cout<<endl<<"请输入圆半径r:";
cin>>r;
cout<<endl<<"圆的周长为"<<c(r);
break;
case 'v':cout<<endl<<"请输入球的半径r:";
cin>>r;
cout<<endl<<"球的体积为"<<v(r);
break;
case 'V':cout<<endl<<"请输入圆柱的底面半径r:";
cin>>r;
cout<<endl<<"请输入圆柱的高h:";
cin>>h;
cout<<endl<<"圆柱的体积为"<<V(r,h);
break;
default: cout<<"您输入的项目不存在!!!"<<endl;
}
}
如果已知了r=2.5,h=4.0,那么就好办了;
void main()
{
float r(2.5),h(4.0);
char m;
cout<<"请输入要计算的项目:圆面积(s);圆周长(c);圆球体积(v);圆柱体积(V):";
cin>>m;
switch(m)
{
case 's':
cout<<endl<<"圆的面积为"<<pi*r*r;
break;
case 'c':
cout<<endl<<"圆的周长为"<<2.0*pi*r;
break;
case 'v':
cout<<endl<<"球的体积为"<<3.0*pi*r*r*r/4.0;
break;
case 'V':cout<<endl<<"圆柱的体积为"<<pi*r*r*h;
break;
default: cout<<"您输入的项目不存在!!!"<<endl;
}
}
