void readBinaryWatch(int currHour, int currMin, int n, int indx1, vector<int>& hours, int indx2, vector<int>& minutes, vector<string>& result) {

if(n == 0) {

string solution = to_string(currHour);

char minBuffer[2];

sprintf(minBuffer, "%02d", currMin);

solution += ":";

solution += string(minBuffer);

result.push_back(solution);

return;

}

if(indx2 >= minutes.size()) {

return;

}

for(int i = indx1; i < hours.size(); ++i) {

if(currHour + hours[i] >= 12) {

break;

}

readBinaryWatch(currHour + hours[i], currMin, n - 1, indx1 + 1, hours, indx2, minutes, result);

}

for(int i = indx2; i < minutes.size(); ++i) {

if(currMin + minutes[i] >= 60) {

break;

}

readBinaryWatch(currHour, currMin + minutes[i], n - 1, indx1, hours, indx2 + 1, minutes, result);

}

}

vector<string> readBinaryWatch(int num) {

vector<int> hours {1, 2, 4, 8};

vector<int> minutes {1, 2, 4, 8, 16, 32};

vector<string> result;

if(num > hours.size() + minutes.size()) {

return result;

}

readBinaryWatch(0, 0, num, 0, hours, 0, minutes, result);

return result;

}

vector<string> readBinaryWatch(int num) {

vector<string> result;

for (int h = 0; h < 12; h++) {

for (int m = 0; m < 60; m++) {

if (bitset<10>(h << 6 | m).count() == num) {

result.push_back(to_string(h) + (m < 10 ? ":0" : ":") + to_string(m));

}

}

}

return result;

}