说明：  用C语言编程模拟一个拥有若干个虚页的进程在给定的若干个实页中运行、并在缺页中断发生时使用LRU算法进行页面置换的情形
(With C language programming simulate a virtual page has a number of processes in a given number of real pages to run, and the page fault occurs, using the LRU algorithm for page replacement case)