I am trying to solve a problem, a part of which requires me to calculate (2^n)%1000000007 , where n<=10^9. But my following code gives me output "0" even for input like n=99.

Is there anyway other than having a loop which multilplies the output by 2 every time and finding the modulo every time (this is not I am looking for as this will be very slow for large numbers).

#include<stdio.h>
#include<math.h>
#include<iostream>
using namespace std;
int main()
{
    unsigned long long gaps,total;
    while(1)
    {
        cin>>gaps;
        total=(unsigned long long)powf(2,gaps)%1000000007;
        cout<<total<<endl;
    }
}