Compilare: user.cpp: In function ‘int main()’: user.cpp:42:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<v.size();i++) fout<<v[i]<<" "; ^ user.cpp:41:11: warning: ‘r’ may be used uninitialized in this function [-Wmaybe-uninitialized] fout<<r<<"\n"; ^