Compilare: user.cpp: In function ‘int main()’: user.cpp:68:9: warning: unused variable ‘a’ [-Wunused-variable] int a= fib[n-2], b= fib[n-1], a2, x, y, ok= 0; ^ user.cpp:68:22: warning: unused variable ‘b’ [-Wunused-variable] int a= fib[n-2], b= fib[n-1], a2, x, y, ok= 0; ^ user.cpp:68:35: warning: unused variable ‘a2’ [-Wunused-variable] int a= fib[n-2], b= fib[n-1], a2, x, y, ok= 0; ^