Question

Java

Looking for some help on getting this started. Directions below.

Operating systems designers have long used simulation as an inexpensive way to test new algorithms. In this assignment you write a Java program that prompts the user for simulation data then runs a selected page replacement algorithm on that system, reporting frame assignments and total page faults.

Instructions

Your program will prompt the user first for the number of frames to be used in the simulation, then for a page access string, where page numbers (positive) are separated by one or more spaces. Reprompt on invalid input.

Please enter the number of frames: abc
Please enter the number of frames: 5
Please enter the page reference string: 1 2 1 4 3 6 3 4 5 1 2 8 6 7 2 5 3 4 1 7 8

Next, prompt the user to select one of 3 page replacement algorithms: FIFO, Optimal, or LRU

Please enter 1. for FIFO, 2. for Optimal, or 3. for LRU: 1

Finally assuming pure demand paging show the page to frame mapping for each page fault, and count the total number of page faults.

1 -> 1
2 -> 2
4 -> 3
3 -> 4
6 -> 5
5 -> 1
1 -> 2
2 -> 3
8 -> 4
7 -> 5
3 -> 1
4 -> 2
12 page faults.

Answer 1

java code:

import java.util.*;
public class Main
{
   public static void main(String[] args) throws java.util.InputMismatchException
   {

int j,i,k,no,count=0;
int a[]=new int[100];
int frame[]=new int[10];
int pos,value, n;
Scanner s=new Scanner(System.in);
  
  
System.out.println("enter number for pages:");
n=s.nextInt();
System.out.println("enter page numbers:\n");
for(i=0;i<n;i++)
{
a[i]=s.nextInt();
}

System.out.println("enter no for frames:\n");
no=s.nextInt();
for(i=0;i<no;i++)
frame[i]=-1;
if(no==(int)no)
{
  
j=0;
pos=0;
value=a[j];
while(j<n)
{
for(i=0;i<no;i++)
{
if(frame[i]==value)
{
j++;
break;
}
if(i==2)
{
frame[pos]=value;
j++;
pos++;
for(i=0;i<no;i++)
{
System.out.print(" \t"+frame[i]);
}
count++;
System.out.println("\n");
}
if(pos==no)
{
pos=0;
}
}
value=a[j];
}
}
else
System.out.println("invaild input:");
  

System.out.println(" page defaults are:"+count);
  

   }
}

output: