Compilare: user.cpp: In function ‘bool ok_dfs(int)’: user.cpp:16:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<V[nod].size();++i) ^ user.cpp:17:53: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j=0,sursa=V[nod][i];j<V[sursa].size();++j) ^ user.cpp:18:59: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int k=0,neveu=V[sursa][j];k<V[neveu].size();++k) ^