50. Pow(x, n)

class Solution {
public:
    double myPow(double x, int n) {
        double ans=1.0;
        long long nn=n;
        if(nn<0)
            nn = -1*nn;
        while(nn>0){
            if(nn%2==0){//For Even
                x=x*x;
                nn=nn/2;
            }else{//For Odd
                ans=ans*x;
                nn=nn-1;
            }
        }
        if(n<0)
            return ans=(double)1/ans;
        return ans;
    }
};