用C语言或C++语言设计一个最多包括N个用户的多用户文件系统，约定每个用户最多保存M个文件。 同时相知一个用户在进入系统后，最多打开L个文件。-Using C language or C++ language design, including a maximum of N user multi-user file system, agreed to preserve each user a maximum of M documents. At the same time, know eac