Compilare: user.cpp: In function ‘void DFS(const int&)’: user.cpp:21:37: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < L[node].size(); i ++) ^ user.cpp: In function ‘int main()’: user.cpp:51:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < G.size(); i ++) ^