Compilare: user.cpp: In function ‘void dfs_down(int)’: user.cpp:22:36: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < G[nod].size(); ++i){ ^ user.cpp: In function ‘void dfs_up(int, int)’: user.cpp:37:36: 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:64:10: warning: ‘ans2’ may be used uninitialized in this function [-Wmaybe-uninitialized] g << ans2 << ' ' << ans << '\n'; ^