Compilare: user.cpp:16:1: warning: ‘typedef’ was ignored in this declaration [enabled by default] }; ^ user.cpp: In function ‘int main()’: user.cpp:47:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0; i<v[1].size(); ++i) ^ user.cpp:57:36: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0; i<v[a.b].size(); ++i) ^