Compilare: user.cpp: In function ‘int main()’: user.cpp:15:6: warning: unused variable ‘a1’ [-Wunused-variable] int a1,a2,b1,b2; ^ user.cpp:15:9: warning: unused variable ‘a2’ [-Wunused-variable] int a1,a2,b1,b2; ^ user.cpp:15:12: warning: unused variable ‘b1’ [-Wunused-variable] int a1,a2,b1,b2; ^ user.cpp:15:15: warning: unused variable ‘b2’ [-Wunused-variable] int a1,a2,b1,b2; ^