c++ possible solution

    void recurseLoop(const vector<string>& sout, int numLoops)
    {
        if(numLoops > 0)
        {
            for (int i = 0; i < sout[sout.size() - numLoops].size(); i++)
            {
                cout << i;
                recurseLoop(sout, numLoops - 1);
                cout << endl;
            }

        }
        else
        {
            return;
        }
    }

is:

000
1
2

10
1
2

20
1
2