Compilare: user.cpp: In function ‘void get_number(int&)’: user.cpp:39:40: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(buff, 1, dmax, stdin); ^ user.cpp:50:40: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(buff, 1, dmax, stdin); ^ user.cpp: In function ‘int main()’: user.cpp:68:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("mayonaka.in", "r", stdin); ^ user.cpp:69:41: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("mayonaka.out", "w", stdout); ^