Compilare: user.cpp: In function ‘int main()’: user.cpp:19:27: warning: passing NULL to non-pointer argument 3 of ‘std::basic_istream<_CharT, _Traits>& std::basic_istream<_CharT, _Traits>::getline(std::basic_istream<_CharT, _Traits>::char_type*, std::streamsize, std::basic_istream<_CharT, _Traits>::char_type) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_istream<_CharT, _Traits>::char_type = char; std::streamsize = int]’ [-Wconversion-null] f.getline(sir,1000,NULL); ^ user.cpp:13:38: warning: unused variable ‘x’ [-Wunused-variable] int n,a,b,i,j,suma,contor=0,*v,m,x,k; ^ user.cpp:13:40: warning: unused variable ‘k’ [-Wunused-variable] int n,a,b,i,j,suma,contor=0,*v,m,x,k; ^ user.cpp:14:22: warning: unused variable ‘aux’ [-Wunused-variable] char sir[100002],aux[20]; ^