Code 11

----------LRU Page Replacement----------
----------Code 11----------

import java.io.*;
import java.util.*;
public class LRU {

    public static void main(String[] args) throws IOException
    {
        BufferedReader br = new BufferedReader (new InputStreamReader(System.in));
        int frames, pointer = 0, hit = 0, fault = 0, ref_len;
        Boolean isFull = false;
        int buffer[];
        ArrayList<Integer> stack = new ArrayList<Integer> ();
        int reference[];
        int mem_layout[][];
        System.out.println("Please enter the number of Frames: ");
        frames = Integer.parseInt(br.readLine());
        System.out.println("Please enter the length of the Reference string:");
        ref_len = Integer.parseInt(br.readLine());
        reference = new int[ref_len];
        mem_layout = new int[ref_len][frames];
        buffer = new int[frames];
        for(int j = 0; j < frames; j++)
        buffer[j] = -1;

        System.out.println("Please enter the reference string: ");
        for(int i = 0; i < ref_len; i++)
        {
        reference[i] = Integer.parseInt(br.readLine());
        }
        System.out.println();
        for(int i = 0; i < ref_len; i++)
        {
        if(stack.contains(reference[i]))
        {
        stack.remove(stack.indexOf(reference[i]));
        }
        stack.add(reference[i]);
        int search = -1;
        for(int j = 0; j < frames; j++)
        {
        if(buffer[j] == reference[i])
        {
        search = j;
        hit++;
        break;
        }
        }
        if(search == -1)
        {
        if(isFull)
        {
        int min_loc = ref_len;
        for(int j = 0; j < frames; j++)
        {
        if(stack.contains(buffer[j]))
        {
        int temp = stack.indexOf(buffer[j]);
        if(temp < min_loc)
        {
        min_loc = temp;
        pointer = j;
        }
        }
        }
        }
        buffer[pointer] = reference[i];
        fault++;
        pointer++;
        if(pointer == frames)
        {
        pointer = 0;
        isFull = true;
        }
        }
        for(int j = 0; j < frames; j++)
        mem_layout[i][j] = buffer[j];
        }
        for(int i = 0; i < frames; i++)
        {
        for(int j = 0; j < ref_len; j++)
        System.out.printf("%3d ",mem_layout[j][i]);
        System.out.println();
        }
        System.out.println("The number of Hits: " + hit);
        System.out.println("Hit Ratio: " + (float)((float)hit/ref_len));
        System.out.println("The number of Faults: " + fault);
    }
}