是flu算法 是在命令行中输入数据流来进行调度，有计算缺页率。不是从txt中读取。是为了。LFU是最近最不常用页面置换算法(Least Frequently Used),也就是淘汰一定时期内被访问次数最少的页!要求在页置换时置换引用计数最小的页，因为经常使用的页应该有一个较大的引用次数-Main page scheduling algorithm: FIFO, least recently used scheduling algorithm (LRU), least recently used scheduling algorithm (LFU), the best algorithm (OPT) subject requirements: ① the realization of the three algorithms: 1, FIFO 2, OPT 3, LRU ② page sequence　the specified text file (TXT files) out of ③ Output: the first line: every time out the page number, the second line: shows the total number of missing pages