Compilare: user.cpp: In function ‘int main()’: user.cpp:65:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<v[0].size();i++) ^ user.cpp:82:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j=0;j<af[i].size();j++) ^