一些小问题,

[海兴lps]

#include <iostream>
using namespace std;
class circle
{
public:
GetAera();
circle (float r);
private:
radium;
};
float circle::GetAera()
{ float area;
area=3.14*radium*radium;
return area;
}
circle::circle(float r)
{radium=r}
main()
{
float radium;
float area;
cin>>radium;
circle pool(radium);
area=pool.GetAera();
cout<<area<<endl;
}

[zsj2008deadapple]

#include <iostream>
using namespace std;

class circle
{
public:
float GetAera();
circle(float r);

private:
float radium;
};

float circle::GetAera()
{
float area;
area = 3.14f * radium * radium;
return area;
}
circle::circle(float r)
{
radium = r;
}

void main()
{
float radium;
float area;
cin >> radium;

circle pool(radium);

area = pool.GetAera();

cout << area <<endl;
}

[tiantang1fu]

#include <iostream> 
using namespace std; 

class circle 
{ 
public: 
float GetAera(); 
circle(float r); 

private: 
	float radium; 
}; 

float circle::GetAera() 
{  
	float area; 
	area = 3.14f * radium * radium; 
    return area; 
} 
circle::circle(float r) 
{ 
	radium = r; 
} 

void main() 
{ 
	float radium; 
	float area; 
	cin >> radium; 
	
	circle pool(radium); 
	
	area = pool.GetAera(); 
	
	cout << area <<endl; 
}

[海兴lps]

上边程序哪里错了?请假大家啊.

[HotHat]

#include <iostream>
using namespace std;
class circle
{
public:
GetAera(); //少了float
circle (float r);
private:
radium;
};
float circle::GetAera()
{ float area;
area=3.14*radium*radium;
return area;
}