Compilare: user.cpp: In function ‘void bf()’: user.cpp:31:9: warning: unused variable ‘i’ [-Wunused-variable] int i,j; ^ user.cpp:31:11: warning: unused variable ‘j’ [-Wunused-variable] int i,j; ^ user.cpp: In function ‘int main()’: user.cpp:103:9: warning: unused variable ‘i’ [-Wunused-variable] int i; ^