Compilare: user.cpp: In function ‘int bf()’: user.cpp:30: warning: comparison between signed and unsigned integer expressions user.cpp: In function ‘int bf2(int)’: user.cpp:52: warning: comparison between signed and unsigned integer expressions user.cpp:62: warning: no return statement in function returning non-void user.cpp: In function ‘int main()’: user.cpp:78: warning: comparison between signed and unsigned integer expressions user.cpp:104: warning: suggest parentheses around ‘&&’ within ‘||’