Compilare: user.cpp: In function 'int main()': user.cpp:68: warning: comparison between signed and unsigned integer expressions user.cpp:80: warning: comparison between signed and unsigned integer expressions user.cpp:58: warning: 'a' may be used uninitialized in this function /tmp/ccU535Ej.o: In function `main': user.cpp:(.text+0x21d): warning: the `gets' function is dangerous and should not be used.