编写一个程序，模拟一个页式虚拟存储管理系统。（不考虑地址转换）

其中，由系统随机产生进程；

进程大小、进程到达次序、时间、进程执行轨迹（页面访问顺序）也随机生成，但进程之间必须有并发存在，进程执行时间需有限，进程调度采用时间片轮转算法（以页面模拟）；

物理块分配策略采取固定分配局部置换；

分配算法采用按比例分配算法；

调页采用请求调页方式；

置换采用LRU算法；

驻留集大小可调，观察驻留集大小对缺页率的影响。-Write a program that simulates a paged virtual memory management system. (Without regard to the address conversion) wherein the system generates a random process　process size, the process order of arrival, time, the process execution trace (page access sequence) is randomly generated, but there must exist between concurrent processes, the process time required to perform a limited process scheduling algorithm using time slice (page-analog)　physical block allocation strategy to take a fixed allocation of partial replacement　allocation algorithm using a pro rata allocation algorithm　paging using demand paging mode　replacement using LRU algorithm　resident set size adjustable observe the resident set size affect the rate of missing pages.