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This article mainly introduces "how to realize the python slice simulation LRU algorithm". In the daily operation, I believe many people have doubts about how to realize the python slice simulation LRU algorithm. The editor consulted all kinds of data and sorted out a simple and easy-to-use operation method. I hope it will be helpful to answer the doubt of "how to realize the python slice simulation LRU algorithm". Next, please follow the editor to study!

Problem description: a process has just obtained the right to use three main memory blocks, if the order of the process to visit the page is 1meme2, 3, 4, 1, 2, 5, 5, 1, 5, 4, 4, 4, 5. What is the number of page faults that occur when using the LRU algorithm?

Hint:LRU (Least Recently Used) means the least recently used.

This algorithm is often used in page replacement algorithms. When the new page we want to visit is not in main memory, remove the least recently used page from main memory and store the new page in main memory. A queue can be used to simulate this algorithm: the currently visited page is at the end of the queue, the most recently visited page is at the head of the queue, if the newly visited page is in the queue, move this page to the end of the queue, and the other pages move forward in turn; if the newly visited page is not in the queue, move the head of the queue and move the other pages forward, and the new page to be visited joins the queue. The so-called missing page means that there are no pages that need to be accessed in main memory.

Simulate the LRU algorithm with python:

List= [1,2,3,4,1,2,5,1,2,3 4Magazine 5] # this list stores the pages to be visited await list = [] # this list is used to simulate the main memory in the LRU algorithm to store a maximum of 3 count=0 # record the number of missing pages tag=1 # mark whether the missing page for i in List: # list elements to be accessed If i not in a_list: # if the element you want to access is not in a_list, it is count+=1 tag=1 if len (a_list).

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