Compilare: user.cpp: In function 'int nxt(int)': user.cpp:31: warning: comparison between signed and unsigned integer expressions user.cpp: In function 'void process()': user.cpp:42: warning: comparison between signed and unsigned integer expressions user.cpp:37: warning: unused variable 'nr' user.cpp: In function 'void euler(int)': user.cpp:85: warning: comparison between signed and unsigned integer expressions user.cpp: In function 'int main()': user.cpp:132: warning: comparison between signed and unsigned integer expressions user.cpp:155: warning: comparison between signed and unsigned integer expressions