Compilare: user.cpp: In function ‘int main()’: user.cpp:55:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j=0;j<dv.size();++j) { ^ user.cpp:70:22: warning: ‘s2’ may be used uninitialized in this function [-Wmaybe-uninitialized] so<<s1<<' '<<s2<<'\n'; ^ user.cpp:70:13: warning: ‘s1’ may be used uninitialized in this function [-Wmaybe-uninitialized] so<<s1<<' '<<s2<<'\n'; ^