java实现的页面置换算法

• 原理就不说了，直接上代码
• FIFO

import ;
import ;

import ;


/**
 * 
 * 
 * @author cnkeysky
 *
 */

public class FIFO {

    public void run() {
        String[] inputStr = {"1", "2", "3", "4", "2", "1", "2", "3", "5", "2", "3", "7", "6"};
        // 内存块
        int memory = 3;
        List<String> list = new ArrayList<>();
        for(int i = 0; i < ; i++){
            if(i == 0){
                (inputStr[i]);
                ("第"+ i +"次访问：\t\t" + (list));
            }else {
                if((list, inputStr[i])){
                    ("第" + i + "次" + "访问：\t\t" + (list));
                }else{
                    if(() < memory){
                        (inputStr[i]);
                    }else{
                    (0);
                    (inputStr[i]);

                    }
                    ("第" + i + "次" + "访问：\t\t" + (list));
                }
            }
        }
    }

}

• LRU

import ;

import ;
import .List;

/**
 * 最近最久未用置换算法
 * @author cnkeysky
 *
 */

public class LRU {

    public static void main(String[] args) {
        String[] inputStr = {"6", "7", "6", "5", "9", "6", "8", "9", "7", "6", "9", "6"};
        // 内存块
        int memory = 3;
        List<String> list = new ArrayList<>();
        for(int i = 0; i < ; i++){
            if(i == 0){
                list.add(inputStr[i]);
                ("第"+ i +"次访问：\t\t" + (list));
            }else {
                if((list, inputStr[i])){
                    // 存在字符串，则获取该下标
                    int index = (list, inputStr[i]);
                    // 下标不位于栈顶时，且list大小不为1时
                    if(!(list.get(list.size() - 1)).equals(inputStr[i]) && list.size() != 1) {
                        String str = list.get(index);
                        list.remove(index);
                        list.add(str);
                    }
                    ("第" + i + "次" + "访问：\t\t" + (list));
                }else{
                    if(list.size()>= memory) {
                        list.remove(0);
                        list.add(inputStr[i]);
                        ("第" + i + "次" + "访问：\t\t" + (list));
                    }else {
                        list.add(inputStr[i]);
                        ("第" + i + "次" + "访问：\t\t" + (list));
                    }
                }
            }
        }
    }
}

• Clock

import ;
import ;

import ;

/**
 * 
 * 
 * @author cnkeysky
 *
 */
public class Clock {

    public static void main(String[] args) {
        String[] inputStr = {"6", "7", "6", "5", "9", "6", "8", "9", "7", "6", "9", "6"};
        List<String> list = new ArrayList<>();
        // 内存块
        int memory = 3;
        // 缺页次数
        int count = 0;
        String[] clock = new String[memory];
        int indexNext = 0;
        int index = 0;
        // 初始化时钟
        for(int i = 0; i < memory; i++) {
            clock[i] = "0";
        }
        for(int i = 0; i < ; i++) {
            int indexPre = 0;
            if (i == 0) {
                (inputStr[i]);
                clock[indexNext] = "1";
                indexNext++;
                ("第"+ i +"次访问：\t\t" + (list));
            }else {

                if((list, inputStr[i])) {
                    indexPre = (list, inputStr[i]);
                    if(clock[indexPre].equals("0")) {
                        clock[indexPre] = "1";
                    }
                    count++;
                    ("第"+ i +"次访问：\t\t" + (list));
                }else {
                    if(() < memory) {
                        (inputStr[i]);
                        clock[indexNext] = "1";
                        indexNext++;
                        ("第"+ i +"次访问：\t\t" + (list));
                    }else {
                        index = (indexNext, clock, memory);
                        (index);
                        (index, inputStr[i]);
                        clock[index] = "1";
                        indexNext = index + 1;
                        ("第"+ i +"次访问：\t\t" + (list));
                    }
                }
            }
            if(indexNext > memory - 1) {
                indexNext = (memory - indexNext);
            }
        }
        ("缺页次数：" + (-count));
    }

}

• 工具类ListUtils

import ;

public class ListUtils {

    public ListUtils() {

    }

    /**
     * 输出
     * @param list 将List转为数组并输出, out: 2, 3, 4 
     * @return
     */
    public static String listToString(List list){

        StringBuffer content = new StringBuffer();
        for(int i = 0; i < (); i++){
            ((i));
            if(i < () - 1){
                (",");
            }
        }
        return ();
    }

    /**
     * 在list中查找是否有str
     * @param list
     * @param str
     * @return
     */
    public static boolean find(List<String> list, String str){
        boolean flag = false;
        for(String lis : list){
            if((str)){
                flag = true;
            }
        }
        return flag;
    }

    /**
     * 在List中查找是否有String,如果有返回下标, 否则返回 -1
     * @param list
     * @param str
     * @return
     */
    public static int findIndex(List<String> list, String str) {

        int index = 0;
        for(String lis : list) {
            if((str)) {
                return index;
            }
            index++;
        }
        return -1;
    }

    public static boolean clockJudge(String[] clock, int index) {
        if(clock[index].equals("0")) {
            return true;
        }
        return false;
    }
    /**
     * 
     * @param index 下标
     * @param clock 时钟
     * @param range 当前使用内存块
     * @return
     */
    public static int findZero(int index, String[] clock, int range) {

        while(true) {

            if(clock[index].equals("0")) {
                break;
            }else {
                clock[index] = "0";
                index++;
                if(index > range-1) {
                    index = (range - index);
                }
            }
        }
        return index;
    }

    /**
     * 在数组中查找是否存在该字符串
     * @param obj
     * @param str
     * @return
     */
    public static boolean strJudge(Object[] obj, String str) {
        boolean flag = false;
        if(obj == null) {
            return flag;
        }
        for(int i = 0; i < ; i++) {
            if((obj[i])) {
                flag = true;
                break;
            }
        }
        return flag;
    }

    /**
     * 获取二维数组中同一列的行的长度
     * @param str 数据
     * @param length 二维数组的列
     * @param memory 内存块
     * @return
     * 
     */

    public static int findNull(Object[][] str, int length, int memory) {

        int index = 0;
        if(str == null) {
            return -1;
        }
        for(int i = 0; i < memory; i++) {
            if(str[i][length] != null) {
                index = i;
            }
        }
        return index;
    }
}