combination of 5 people into 3 prison cells

main.cpp

#include <iostream>
#include <vector>
#include <string>
#include <algorithm>

void enumerate(
    const int n,
    const int r,
    const int start_at,
    std::vector<std::string>& labels,
    std::vector<std::string>& enumed
)
{
    if (enumed.size() == r)
    {
        for (auto &el : enumed)
        {
            std::cout << el << " ";
        }
        std::cout << std::endl;
        return;
    }

    for (int i = start_at; i < n; i++)
    {
        auto current = labels.at(i);
        enumed.push_back(current);
        enumerate(n, r, i+1 ,labels, enumed);
        enumed.pop_back();
    }
}

int main() {
    std::vector<std::string> labels = {"Muhamad Rava Basya", "Basya", "Muhamad", "Rava", "Raba"};
    int n = labels.size(),
        r = 3;

    std::vector<std::string> enumed;

    enumerate(n, r, 0, labels, enumed);

    for(const auto & i : enumed) {
        std::cout << i << std::endl;
    }

    return 0;
}