Compilare: user.cpp:44:2: warning: no newline at end of file user.cpp: In function 'int main()': user.cpp:19: warning: comparison between signed and unsigned integer expressions user.cpp:20: warning: comparison between signed and unsigned integer expressions user.cpp:21: warning: comparison between signed and unsigned integer expressions user.cpp:25: warning: comparison between signed and unsigned integer expressions user.cpp:33: warning: comparison between signed and unsigned integer expressions