Compilare: user.cpp: In function 'int main()': user.cpp:42: warning: comparison between signed and unsigned integer expressions user.cpp:55: warning: comparison between signed and unsigned integer expressions user.cpp:56: warning: comparison between signed and unsigned integer expressions user.cpp:57: warning: comparison between signed and unsigned integer expressions user.cpp:71: warning: comparison between signed and unsigned integer expressions user.cpp:72: warning: comparison between signed and unsigned integer expressions user.cpp:89: warning: format '%d' expects type 'int', but argument 3 has type 'long long unsigned int'