程序代码：

#include <iostream>
using namespace std;
double add (double x,double y)
{
       return x+y;
}
double subtraction (double x,double y)
{
       return x-y;
}
double calculate ( double x,double y,double (*p[3])(double,double))//这样定义有错吗？
{
       double *p[0](double,double)=add;//这里报错
       double *p[1](double,double)=subtraction;
       return (*p)(x,y);
}
int main ()
{
    double add (double x,double y);
    double subtraction (double x,double y);
    double calculate ( double x,double y,double (*p[2])(double,double));
    double a,b;
    cout<<"Please input figure:";
    while (cin>>a>>b)
    {
          for (int i=0;i<2;i++)
          {
              cout<<calculate (a,b,p[i])<<endl;
          }
          cout<<"Please input figure:";
    }
    system("pause");
    return 0;
}