Compilare: user.cpp: In function ‘void ve()’: user.cpp:22:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<v[r].size();i++) ^ user.cpp: In function ‘void ve2()’: user.cpp:42:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<v[r].size();i++) ^