class Solution {

public:

    double pow(double x, int n)

    {

        double a=1;

        if(n==0)return 1;

        if(x==1)return 1;

        if(x==-1)

        {

            if(n&1)return -1;

            else return 1;

        }

        int absn=abs(n);

        a=power(x,absn);

        if(n<0)

        {

            a=1/a;

        }

        return a;

    }

    double power(double x,int n)

    {

        double result=1;

        if(n==1)return x;

        if(n&1)

        {

          result*=x;

          n=n-1;

        }

        double temp=power(x,n>>1);

        result=result*temp*temp;

        return result;

    }

};