Compilare: user.cpp: In function ‘int main()’: user.cpp:133:33: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(&head, 14, 1, fin); ^ user.cpp:134:37: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(&infohead, 40, 1, fin); ^ user.cpp:142:48: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(&M[15 - i][j], 3, 1, fin); ^