Compilare: user.cpp: In member function ‘std::vector<int> directed_graph::getDistance(const int&)’: user.cpp:37:36: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i <G[node].size(); ++i) { ^ user.cpp: In function ‘int main()’: user.cpp:62:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < dist.size(); ++i) { ^