全排列问题

//全排列问题
void Perm(string list, int i)
{
    if (i == list.length())
    {
        for (int c = 0; c < list.length(); c++)
        {
            cout << list.at(c) << "  ";
        }
        cout << "\n";
    }
    else
    {
        for (int j = i; j < list.length(); j++)
        {
            swap(list.at(i), list.at(j));
            Perm(list,i+1);
            swap(list.at(i),list.at(j));
        }
    }
}