编一个求x的n次方的函数
#include <iostream.h>
double cf(double x,int n)
{
    double b=1;
    for(int a=1;a<=n;a++)
    {
        b*=a;
        return b;
    }
}
void main()
{
    double x;int n;
    cout<<"请输入X和N的值"<<endl;
    cin>>x>>n;
    cout<<x<<"的"<<n<<"次方为:"<<cf(x,n)<<endl;
}

请楼上高手指导下