Compilare: user.cpp: In function ‘void dfs(int)’: user.cpp:17:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < N[nod].size (); i++) { ^ user.cpp: In function ‘int main()’: user.cpp:29:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j = 0; j < N[x].size (); j++) { ^