hdu 5363 Key Set 快速幂

#include<cstdio>
#include<cstring>
using namespace std;
long long t,n,ans,y;
int f()
{
    ans=1;
    y=2;;
    n-=1;
    while (n)
    {
        if (n&1) ans=(ans*y)%1000000007;
        y=(y*y)%1000000007;
        n>>=1;
    }
    return ans-1;
}
int main()
{
    scanf("%lld",&t);
    while (t--)
    {
        scanf("%lld",&n);
        printf("%lld\n",f());
    }
    return 0;
}