std::vector<std::vector<int>> AEGraph::possible_double_cuts() const {
    /*folosim un stack pentru a introduce fiecare subgraf,
      in cazul in care nu are atomi si nu este SA atunci se poate face
      operatia de double cut*/
	std::vector<std::vector<int>> paths;
	std::stack<AEGraph> my_stack;
	my_stack.push(*this);
	while(!my_stack.empty()) {
		auto aux = my_stack.top();
		my_stack.pop();
		if(!aux.is_SA && aux.num_atoms() == 0) {
			if(get_paths_to(aux).size())
                /*in cazul in care  exista path-ul, il introducem drept
                  path pentru subgraful corect*/
			paths.push_back(get_paths_to(aux)[get_paths_to(aux).size() - 1]);
		}
		for (int i = 0; i < aux.num_subgraphs(); ++i) {
			my_stack.push(aux.subgraphs[i]);
		}
	}
	return paths;
 }

AEGraph AEGraph::double_cut(std::vector<int> where) const {
	std::string string_final= {};

	auto aux = this->subgraphs[where[0]];

    /*varianta originala a grafului*/
	string_final = this->repr();

	for (unsigned int i = 1; i < where.size(); i++){
		aux = aux.subgraphs[where[i]];
	}

    /*stringul subgrafului caruia trebuie sa i se aplice double cut*/
	std::string string_gresit = aux.repr();

    /*o copie a stringului anterior din care stergem 2 perechi de paranteze*/
	std::string string_corect = string_gresit;

	string_corect.erase(string_corect.begin(), string_corect.begin() + 2);
	string_corect.erase(string_corect.end() - 2, string_corect.end());

    /*inlocuim string-ul gresit cu cel modificat in interiorul stringului
     grafului original*/
	int found = string_final.find(string_gresit);
	string_final.replace(found, string_gresit.length(), string_corect);

    return AEGraph(string_final);
}