divisors from factors

#include<iostream>
#include<vector>

using namespace std;

vector<long> divs(vector<vector<int>> fs, int s, int e){
    vector<long> r;
    if (e == s){
        vector<int> fa = fs[s];
        long c = 1, p = 0;
        while (p <= fa[1]){
            r.push_back(c);
            c *= fa[0];
            p++;
        }
        return r;
    }
    vector<long> sr = divs(fs, s + 1, e);
    //cout << "s, e: " << s + 1 << ", " << e << "\n";
    //for (int i = 0; i < sr.size(); i++){
        //cout << sr[i] << ", ";
    //}cout << endl;

    vector<int> fa = fs[s];
    long c = 1, p = 0;
    while (p <= fa[1]){
        // r.add(p);
        for (long n : sr){
            r.push_back(n*c);
        }
        c *= fa[0];
        p++;
    }
    return r;
}

int main(){

    vector<vector<int>> fs;
    fs.push_back({ 2, 2 });
    fs.push_back({ 3, 1 });
    //fs.push_back({ 5, 3 });

    vector<long> d = divs(fs, 0, fs.size() - 1);

    for (int i = 0; i < d.size(); i++){
        cout << d[i] << ", ";
    }cout << endl;

    getchar();
    return 0;
}