Compilare: user.cpp: In member function ‘void numar::print_number()’: user.cpp:70:30: warning: format ‘%d’ expects argument of type ‘int’, but argument 2 has type ‘ull {aka long long unsigned int}’ [-Wformat=] printf("%d", c[i]); ^ user.cpp: In function ‘int main()’: user.cpp:101:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("algebra2.in","r",stdin); ^ user.cpp:102:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("algebra2.out","w",stdout); ^