Compilare: user.cpp: In function 'int nxt(int)': user.cpp:30: warning: comparison between signed and unsigned integer expressions user.cpp: In function 'void process()': user.cpp:41: warning: comparison between signed and unsigned integer expressions user.cpp:36: warning: unused variable 'nr' user.cpp: In function 'int main()': user.cpp:128: warning: comparison between signed and unsigned integer expressions user.cpp:153: warning: comparison between signed and unsigned integer expressions