五年计划是什么:紧急，谁帮我写个C＋＋程序

class CNumber
{
public:
int operator+(const int);
int operator-(const int);
int operator*(const int);
double operator/(const int);
int operator!(const int);
double sqrt(const int);
}

这样可以不？
#include <iostream.h>
#include <math.h>

class CNumber
{
public :
int Add(int a,int b);
int Sub(int a,int b);
int Mul(int a,int b);
double Div(int a,int b);
int JieChen(int a);
double Sqrt(int a);
};

int CNumber::Add(int a,int b)
{
return a+b;
}
int CNumber::Sub(int a,int b)
{
return a-b;
}
int CNumber::Mul(int a,int b)
{
return a*b;
}
double CNumber::Div(int a,int b)
{
return double(a)/double(b);
}
int CNumber::JieChen(int a)
{
int s;
for(int i=1;i<=a;i++)
s*=i;
return s;
}
double CNumber::Sqrt(int a)
{
return sqrt(a);
}

void main()
{
CNumber cnum;
int a=15,b=39;
cout<<"a+b="<<cnum.Add(a,b)<<endl<<"a-b="<<cnum.Sub(a,b)
<<endl<<"a*b="<<cnum.Mul(a,b)<<endl<<"a/b="<<cnum.Div(a,b)
<<endl<<"a!="<<cnum.JieChen(a)<<endl
<<"Sqrt(a)="<<cnum.Sqrt(a)<<endl;

}