Римская система счисления

...
string C[MAXR] = {"I", "V", "X", "L", "C", "D", "M"};
int X[MAXR] = {1, 5, 10, 50, 100, 500, 1000};
...
    R.clear();
    for (int i = 0; i < MAXR; i++)
        R.push_back(make_pair(X[i], C[i]));

    for (int i = 0; i < MAXR; i += 2)
        for (int j = i + 1; j < i + 3 && j < MAXR; j++)
            R.push_back(make_pair(X[j] - X[i], C[i] + C[j]));

    sort(R.rbegin(), R.rend());

    for (int i = 0; i < (int)R.size(); i++)
    {
        for (int j = 0; j < x / R[i].first; j++)
            cout << R[i].second;
        x %= R[i].first;
    }
    cout << endl;
...