#include <iostream>
#include <vector>
 
bool increase(const std::vector<std::size_t>& v, std::vector<std::size_t>& it)
{
    for (std::size_t i = 0, size = it.size(); i != size; ++i) {
        const std::size_t index = size - 1 - i;
        ++it[index];
        if (it[index] > v[index]) {
            it[index] = 0;
        } else {
            return true;
        }
    }
    return false;
}
 
void do_job(const std::vector<std::size_t>& it)
{
    for (const auto e : it) {
        std::cout << e << " ";
    }
    std::cout << std::endl;
}
 
void iterate(const std::vector<std::size_t>& v)
{
    std::vector<std::size_t> it(v.size(), 0);
 
    do {
        do_job(it);
    } while (increase(v, it));
}
 
int main(int argc, char *argv[])
{
    std::vector<std::size_t> v = {0,0,2,3,0,1};
 
    iterate(v);
    return 0;
}