Compilare: user.cpp: In function ‘int bf()’: user.cpp:23: warning: comparison between signed and unsigned integer expressions user.cpp: In function ‘int main()’: user.cpp:51: warning: name lookup of ‘i’ changed user.cpp:7: warning: matches this ‘i’ under ISO standard rules user.cpp:41: warning: matches this ‘i’ under old rules user.cpp:51: warning: comparison between signed and unsigned integer expressions