Compilare: user.cpp: In function ‘void dfs(int)’: user.cpp:40:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i=0; i<G[nod].size(); i++) ~^~~~~~~~~~~~~~ user.cpp: In function ‘int main()’: user.cpp:66:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i=0; i<v.size(); i++) ~^~~~~~~~~