lru.java

package SPOS;

import java.util.*;
public class lru {

    public static void main(String[] args)
    {
    	Scanner sc=new Scanner(System.in);
        int nframe,pointer = 0, h = 0, f = 0,str_len;
        Boolean isFull = false;
        int buffer[];
        ArrayList<Integer> stack = new ArrayList<Integer>();
        int str[];
        int mem_layout[][];
        
        System.out.println("Please enter the number of Frames: ");
        nframe = sc.nextInt();
        
        System.out.println("Please enter the length of the Reference string: ");
        str_len = sc.nextInt();
        
        str = new int[str_len];
        mem_layout = new int[str_len][nframe];
        buffer = new int[nframe];
        for(int j = 0; j < nframe; j++)
        {
        	buffer[j] = -1;
        }
        
        System.out.println("Please enter the reference string: ");
        for(int i = 0; i < str_len; i++)
        {
            str[i] = sc.nextInt();
        }
        System.out.println();
        
        for(int i = 0; i < str_len; i++)
        {
            if(stack.contains(str[i]))
            {
             stack.remove(stack.indexOf(str[i]));
            }
            stack.add(str[i]);
            int search = -1;
            for(int j = 0; j < nframe; j++)
            {
                if(buffer[j] == str[i])
                {
                    search = j;
                    h++;
                    break;
                }
            }
            if(search == -1)
            {
             if(isFull)
             {
              int min_loc = str_len;
                    for(int j = 0; j < nframe; j++)
                    {
                     if(stack.contains(buffer[j]))
                        {
                            int temp = stack.indexOf(buffer[j]);
                            if(temp < min_loc)
                            {
                                min_loc = temp;
                                pointer = j;
                            }
                        }
                    }
             }
                buffer[pointer] = str[i];
                f++;
                pointer++;
                if(pointer == nframe)
                {
                 pointer = 0;
                 isFull = true;
                }
            }
            for(int j = 0; j < nframe; j++)
            {
            	mem_layout[i][j] = buffer[j];
            }
        }
        
        for(int i = 0; i < nframe; i++)
        {
        	System.out.print("Frame "+(i+1)+":\t\t");
        	for(int j = 0; j < str_len; j++)
            {
            	System.out.print(mem_layout[j][i]+"\t\t");
            }
            System.out.println();
        }
        
        System.out.println("The number of Hits: " + h);
        System.out.println("The number of Faults: " + f);
        System.out.println("Hit Ratio: " + (float)((float)h/str_len));
        sc.close();
    }
}