Compilare: user.cpp: In function ‘int main()’: user.cpp:38:10: warning: unused variable ‘i’ [-Wunused-variable] long i,j,n; ^ user.cpp:38:12: warning: unused variable ‘j’ [-Wunused-variable] long i,j,n; ^ user.cpp:38:14: warning: variable ‘n’ set but not used [-Wunused-but-set-variable] long i,j,n; ^ user.cpp:39:10: warning: variable ‘f1’ set but not used [-Wunused-but-set-variable] FILE*f1,*f2; ^ user.cpp:39:14: warning: variable ‘f2’ set but not used [-Wunused-but-set-variable] FILE*f1,*f2; ^