1017. Convert to Base -2.cpp

class Solution {
public:
    string baseNeg2(int n) {
        if (n==0) return "0";
        string ans;
        while (n) {
            int r = n % -2;
            n /= -2;
            if (r < 0) {
                r += 2;
                ++n;
            }
            ans.push_back('0' + r);
        }
        reverse(ans.begin(), ans.end());
        return ans;
    }
};