Compilare: user.cpp: In function 'int main()': user.cpp:13: warning: format '%s' expects type 'char*', but argument 3 has type 'char (*)[100]' user.cpp:21: warning: format '%s' expects type 'char*', but argument 3 has type 'char (*)[100]' user.cpp:29: warning: comparison between signed and unsigned integer expressions