最佳页面置换算法，FIFO，LRU的仿真。页面调用和置换过程有动态显示。内存分配页面数目和页面引用串的长度可以进行人工交互输入。 -best pages replacement algorithm, FIFO, the LRU simulation. Page calls and replacement process is dynamic display. Memory allocation of the number of pages and pages cited the lengt