操作系统中的内存置换算法实现，程序中对三种内存置换算法进行了分析，他们分别是：FIFO、LRU、OPT三种算法，并在程序最后列出了三种算法的堆栈调用情况。-Operating system' s memory replacement algorithm, three types of memory replacement algorithm analysis program, they are: FIFO, LRU, OPT three algorithms and listed at t