高速缓存算法类.英文介绍: The Cache class implements a simple caching mechanism with \"least recently used\" (LRU) replacement. It is useful for cases in which you have some memory to spare and you wish to speed up access to frequently used resources

选择页面替换算法；输入一些虚页号能自动生成对应的实页号。-Choose page replacement algorithm Input some virtual page number can automatically generate the corresponding real page number.