Java code to implement the the first fit algorithm?

Answer 1

import java.util.*;

class Partition

{

private int partstart;

private int partend;

private int partsize;

private int prosssize;

private int pid;

//private int intfrag;

private boolean empty;

private Partition next;

Partition Head=null;

public void createDynamicPartitions(int totmem)

{

Partition p=new Partition();

p.partsize=totmem;

//p.prosssize=0;

p.pid=-1;

//p.intfrag=0;

p.empty=true;

p.next=null;

p.partstart=0;

p.partend=totmem-1;

Head=p;

memStatus();

}

private Partition selectFirstHole(int prsize)

{

Partition temp=Head,first=null;

while(temp != null)

{

if (temp.empty && temp.partsize >= prsize)

{

break;

}

temp=temp.next;

}

return first;

}

public void loadProcess(int pid,int prsize)

{

Partition hole=selectFirstHole(prsize);

if(hole null)

System.out.println("There is no Process with ID :"+dpid);

else

memStatus();

}

private void memStatus()

{

Partition temp=Head;

System.out.println("Current Memory Status");

// int totfrag=0;

while(temp != null)

{

if(temp.empty)

System.out.println(temp.partstart+"-"+temp.partend+" : is hole of size "+temp.partsize);

else

System.out.println(temp.partstart+"-"+temp.partend+" :Memory with Process ID "+temp.pid+" of size "+temp.partsize);

//totfrag=totfrag+temp.intfrag;

temp=temp.next;

}

//System.out.println("\n Total Internal Fragmentation : "+totfrag);

}

}

public class FirstFit

{

public static void main(String args[])

{

Scanner sc=new Scanner(System.in);

System.out.println("Enter Total Memory size :");

int totmem=sc.nextInt();

//System.out.println("Enter number of partitions :");

//int numofpartions=sc.nextInt();

//creating partitions

Partition dp=new Partition();

dp.createDynamicPartitions(totmem);

while(true)

{

System.out.println("Menu");

System.out.println("1.Load Process");

System.out.println("2.Remove Process");

System.out.println("3.Exit");

System.out.println("Enter ur Choice : ");

int ch=sc.nextInt();

switch(ch)

{

case 1:

System.out.println("Enetr Process ID : ");

int pid=sc.nextInt();

System.out.println("Enetr Process size : ");

int prsize=sc.nextInt();

dp.loadProcess(pid,prsize);

break;

case 2:

System.out.println("Enetr Process ID : ");

int dpid=sc.nextInt();

dp.removeProcess(dpid);

break;

case 3:

System.exit(0);

//break;

default:

System.out.println("*** Wrong Choice ***\n Choice must be in b/w 1- 3");

}

}

}

}