Compilare: user.cpp: In function ‘int main()’: user.cpp:11:9: warning: unused variable ‘a’ [-Wunused-variable] int a= 0 , b = 0 , n , x ; ^ user.cpp:11:17: warning: unused variable ‘b’ [-Wunused-variable] int a= 0 , b = 0 , n , x ; ^ user.cpp:11:30: warning: unused variable ‘x’ [-Wunused-variable] int a= 0 , b = 0 , n , x ; ^