页面置换算法:用随机数生成页面请求次序，分配一定数量的物理快，用OPT、FIFO、LRU算法计算缺页次数和置换次数-Page replacement algorithm: the random number generator page request order to allocate a certain amount of physical fast, with OPT, FIFO, the LRU algorithm missing page number and the number of replacement