Sword finger offer16- integer power bit operation of numeric value

Original link

Note：

You can put n Integration 2 Let's see , If the current one is 1, Explain that you want to take this one , No 1 Just skip.
It's the template. Remember, it's over

The code is as follows ：

class Solution {
    
public:
    double myPow(double x, int n) {
    
        bool flag = false;
        double ans = 1.0;
        if(n < 0)   flag = true;
        long long k = abs((long long) n);
        while(k){
    
            if(k & 1)   ans *= x;
            x *= x;
            k >>= 1;
        }
        if(flag)    return 1 / ans;
        return ans;
    }
};