Compilare: main.cpp: In function 'int fib2(int)': main.cpp:28:9: warning: variable 'a' set but not used [-Wunused-but-set-variable] int a, b, answer; ^ main.cpp:28:12: warning: variable 'b' set but not used [-Wunused-but-set-variable] int a, b, answer; ^ main.cpp:28:15: warning: unused variable 'answer' [-Wunused-variable] int a, b, answer; ^~~~~~