用重载函数，不知道哪里错了ＴＴ

#include<iostream>
#include<conio.h>
using namespace std;
int getpower(int x,int y)
{
int m;
for(m=1;m<=y;m++)
{
x=x*x;
}
return x;
}
double getpower(double x,int y)
{
int m;
for(m=1;m<=y;m++)
{
x=x*x;
}
return x;
}
int _tmain(int argc, _TCHAR* argv[])
{
int a,m;
double b;
cout<<"请输入两底数:";
cin>>a>>b;
cout<<"请输入指数:";
cin>>m;
cout<<"结果是:"<<getpower(a,m)<<endl;
cout<<"结果是: "<<getpower(b,m)<<endl;
getch();
return 0;
}