实现分页式存储地址转换过程。出现缺页现象时，用到的先进先出FIFO、最近最久未使用LRU、最佳OPT置换算法。-Implement paging address translation storage process. Phenomenon occurs when the missing pages, use the FIFO FIFO, most recently from lack of use LRU, the best OPT replacement algorithm.