页面置换算法包括：最佳(Optimal)置换算法、先进先出(FIFO)算法、最近最久未使用(LRU)算法 -Page replacement algorithm, including: Best (Optimal) replacement algorithm, first in first out (FIFO) algorithm, most recently from lack of use (LRU) algorithm

分别实现最佳置换算法(optimal)、先进先出(FIFO)页面置换算法和最近最久未使用（LRU）置换算法，并给出各算法缺页次数和缺页率。 -Respectively, to achieve optimal replacement algorithm (optimal), First In First Out (FIFO) page replacement algorithm and the most-recently-used recently (LRU) replacement algo

* 1- randomly the no. of page (n) * 2- create a random squnce of n pages * 3- FIFO page Replacement algorithm * 4- optimal page Replacement algorithm- * 1- randomly the no. of page (n) * 2- create a random squnce of n pages * 3- FIFO