#ifndef FUNCTION_H
#define FUNCTION_H

bool isswap(std::vector<int> &, size_t, size_t);
void perm_r(std::vector<int> &, size_t, size_t, std::vector<std::vector<int>> &);
void permutation(std::vector<int> &, std::vector<std::vector<int>> &);

std::ostream &print_arr(const std::vector<int> &vec, std::ostream &os);

#endif