Compilare: user.cpp: In function ‘void create_answer()’: user.cpp:43:12: warning: converting to non-pointer type ‘char’ from NULL [-Wconversion-null] auxr[n]=NULL; ^ user.cpp: In function ‘int main()’: user.cpp:169:11: warning: converting to non-pointer type ‘char’ from NULL [-Wconversion-null] fin[n]=NULL; ^ user.cpp:160:13: warning: unused variable ‘h’ [-Wunused-variable] int i,j,h; ^