LRU（Least Recently Used）页面置换算法

系统管理员 2022-11-27 07:22 182阅读 0赞

LRU（Least Recently Used）页面置换算法——最近最久未使用

**数据结构**：ArrayDeque双端队列

import java.util.ArrayDeque;
    import java.util.Scanner;
    
    public class LRULearn {
        public static void main(String[] args) {
            String Serial = new Scanner(System.in).next();
            LRU lru = new LRU(8);
            lru.VisitPage1(Serial);
            System.out.println(lru.getQueue());
        }
    }
    
    class LRU{
        private int Cache;
        private ArrayDeque<Character> queue=new ArrayDeque<>();
        public ArrayDeque<Character> getQueue() {
            return queue;
        }
        public LRU(int cache) {
            Cache = cache;
        }
    
    /*
        public void VisitPage(String Serial){
            for(int i=0;i<Serial.length();i++){
                if(i<Cache){
                    queue.addFirst(Serial.charAt(i));
                }
                if(queue.contains(Serial.charAt(i))){
                    queue.remove(Serial.charAt(i));
    
                    queue.addFirst(Serial.charAt(i));
                }
                else{
                    queue.removeLast();
    
                    queue.addFirst(Serial.charAt(i));
                }
            }
            //System.out.println(queue);
        }
    */
    
        public void VisitPage1(String Serial){
            for(int i=0;i<Serial.length();i++){
                //先判断满不满
                if (!isFull()){
                    if (!queue.contains(Serial.charAt(i))){
                        queue.addFirst(Serial.charAt(i));
                    }else {
                        queue.remove(Serial.charAt(i));
                        queue.addFirst(Serial.charAt(i));
                    }
                }else {
                    if (!queue.contains(Serial.charAt(i))){
                        queue.removeLast();
                        queue.addFirst(Serial.charAt(i));
                    }else {
                        queue.remove(Serial.charAt(i));
                        queue.addFirst(Serial.charAt(i));
                    }
                }
            }
        }
    
        public boolean isFull(){
            return queue.size()==Cache;
        }
    }