loop_with_variable_depth.cpp

#include <iostream>
#include <sstream>
#include <string>
#include <vector>

using namespace std;

int get_size(int depth)
{
    int r = 0;
    switch (depth)
    {
        case 0: r = 2; break;
        case 1: r = 2; break;
        case 2: r = 3; break;
    }
    return r;
}

void fill_until(vector< string >* v, int depth)
{
    vector< int > depths;
    depths.reserve(depth);

    for (int i = 0; i < depth; ++i)
    {
        depths.push_back(get_size(i));
    }

    vector< int > positions;
    positions.reserve(depth);
    positions.push_back(1);
    int base = 1;

    for (int i = 0; i < depth; ++i)
    {
        base = base * get_size(i);
        positions.push_back(base);
    }

    vector< int > current;
    current.reserve(depth);

    for (int i = 0; i < depth; ++i)
    {
        current.push_back(0);
    }

    for (int i = 0; i < positions[positions.size() - 1]; ++i)
    {
        for (int j = 0; j < depth; ++j)
        {
            current[j] = (i / positions[j]) % depths[j];
        }

        ostringstream oss;

        for (int j = 0; j < depth; ++j)
        {
            oss << current[j];
            oss << ", ";
        }

        v->push_back(oss.str());
    }
}

int main()
{
    const int depth = 3;
    vector< string > v;
    fill_until(&v, depth);

    for (vector< string >::iterator it = v.begin(); it != v.end(); ++it)
    {
        cerr << *it << endl;
    }
}

0, 0, 0, 
1, 0, 0, 
0, 1, 0, 
1, 1, 0, 
0, 2, 1, 
1, 2, 1, 
0, 3, 1, 
1, 3, 1, 
0, 0, 2, 
1, 0, 2, 
0, 1, 2, 
1, 1, 2,