// Jarod42

#include <algorithm>
#include <cassert>
#include <iostream>
#include <iterator>
#include <vector>

template <typename T>
void Permutation(std::vector<T> v)
{
    std::sort(v.begin(), v.end());
    do {
        std::copy(v.begin(), v.end(), std::ostream_iterator<T>(std::cout, " "));
        std::cout << std::endl;
    } while (std::next_permutation(v.begin(), v.end()));
}

template <typename T>
void Combination(const std::vector<T>& v, std::size_t count)
{
    assert(count <= v.size());
    std::vector<bool> bitset(v.size() - count, 0);
    bitset.resize(v.size(), 1);

    do {
        for (std::size_t i = 0; i != v.size(); ++i) {
            if (bitset[i]) {
                std::cout << v[i] << " ";
            }
        }
        std::cout << std::endl;
    } while (std::next_permutation(bitset.begin(), bitset.end()));
}

bool increase(std::vector<bool>& bs)
{
    for (std::size_t i = 0; i != bs.size(); ++i) {
        bs[i] = !bs[i];
        if (bs[i] == true) {
            return true;
        }
    }
    return false; // overflow
}

template <typename T>
void PowerSet(const std::vector<T>& v)
{
    std::vector<bool> bitset(v.size());

    do {
        for (std::size_t i = 0; i != v.size(); ++i) {
            if (bitset[i]) {
                std::cout << v[i] << " ";
            }
        }
        std::cout << std::endl;
    } while (increase(bitset));
}

int main()
{
    std::vector<char> vc{ 'A', 'B', 'C', 'D' };
    std::vector<char> path;
    std::vector<bool> visited(4, false);
    std::cout << "\n------PERMUTATION----------\n";
    Permutation(vc);
    std::cout << "\n------COMBINATION----------\n";
    Combination(vc, 3);
    std::cout << "\n------POWERSET-------------\n";
    PowerSet(vc);
    return 0;
}