Compilare: user.cpp: In function ‘int main()’: user.cpp:57:26: warning: format ‘%lu’ expects argument of type ‘long unsigned int’, but argument 2 has type ‘long long unsigned int’ [-Wformat=] printf("%lu\n", xnew); ^ user.cpp:21:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("cifre4.in", "rt", stdin); ^ user.cpp:22:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("cifre4.out", "wt", stdout); ^