Compilare: user.cpp: In function ‘int main()’: user.cpp:10: warning: comparison between signed and unsigned integer expressions user.cpp:17: warning: comparison between signed and unsigned integer expressions user.cpp:25: warning: comparison between signed and unsigned integer expressions user.cpp:9: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result user.cpp:12: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result