04 - Number Complement.cpp

class Solution {
public:
    int findComplement(int num) {
        vector <int> v;
        while(num > 0){
            v.push_back(num%2);
            num = num/2;
        }
        reverse(v.begin(), v.end());
        for(int i = 0; i<v.size(); i++){
            if(v[i] == 0){
                v[i] = 1;
            }
            else{
                v[i] = 0;
            }
        }
        int res = 0;
        long long temp = 1;
        for(int i = v.size() - 1; i>=0; i--){
            res += temp*v[i];
            temp = temp*2;
        }
        return res;
    }
};