操作系统LRU算法(最近最少使用算法)

太过爱你忘了你带给我的痛 2024-03-31 14:47 63阅读 0赞

## 操作系统LRU算法(最近最少使用算法) ##

![在这里插入图片描述][b448a3e493bb4be9bc9aafc3ba8dfb72.png]

**提交代码**

//
    // Source code recreated from a .class file by IntelliJ IDEA
    // (powered by Fernflower decompiler)
    //
    
    import java.util.HashMap;
    import java.util.Iterator;
    import java.util.Map;
    import java.util.Scanner;
    
    public class Main {
        
        public Main() {
        
        }
    
        static void upData(HashMap<Integer, Integer> map, int num) {
        
            Iterator var2 = map.keySet().iterator();
    
            while(var2.hasNext()) {
        
                Integer i = (Integer)var2.next();
                if (num != i) {
        
                    map.put(i, (Integer)map.get(i) + 1);
                }
            }
    
        }
    
        static void delete(HashMap<Integer, Integer> map) {
        
            Pair t = null;
            boolean flag = false;
            Iterator var3 = map.keySet().iterator();
    
            while(var3.hasNext()) {
        
                Integer i = (Integer)var3.next();
                if (!flag) {
        
                    t = new Pair(i, (Integer)map.get(i));
                    flag = true;
                } else if (t.priortiy < (Integer)map.get(i)) {
        
                    t = new Pair(i, (Integer)map.get(i));
                }
            }
    
            map.remove(t.num);
        }
    
        static void Travse(HashMap<Integer, Integer> map) {
        
            Iterator var1 = map.keySet().iterator();
    
            while(var1.hasNext()) {
        
                Integer i = (Integer)var1.next();
                System.out.print(i + " " + map.get(i) + " || ");
            }
    
            System.out.println();
        }
    
        public static void main(String[] args) {
        
            Scanner in = new Scanner(System.in);
            System.out.println("输入页面数：");
            int numPage = in.nextInt();
            System.out.println("输入内存数：");
            int numMemory = in.nextInt();
            System.out.println("输入内存：");
            int cnt = 0;
            Map<Integer, Integer> map = new HashMap();
            int[] a = new int[numPage + 10];
    
            for(int i = 0; i < numPage; ++i) {
        
                int num = in.nextInt();
                if (map.size() < numMemory) {
        
                    if (!map.containsKey(num)) {
        
                        ++cnt;
                    }
    
                    map.put(num, 0);
                    upData((HashMap)map, num);
                } else if (!map.containsKey(num)) {
        
                    map.put(num, 0);
                    upData((HashMap)map, num);
                    delete((HashMap)map);
                    ++cnt;
                } else {
        
                    map.put(num, 0);
                    upData((HashMap)map, num);
                }
            }
    
            System.out.printf("F' = %.1f%%", (double)cnt / (double)numPage * 100.0D);
        }
    }

[b448a3e493bb4be9bc9aafc3ba8dfb72.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/03/31/d8b36c677b204db09b6148a25a2f87fe.png