Computer Engineering Made Easy

Tuesday, 7 February 2012

Sem 4 Operating System (OS) : FIFO Page replacement Java code / program

Given below is the Java program for FIFO page replacement algorithm.You can also use the DOWNLOAD BOX to download the '.java' file.

import java.util.*;
class FIFO
{
static boolean check(int p[],int n,int x)
{
for(int i=0;i<n;++i)
{
if(p[i]==x)
return true;
}
return false;
}
public static void main(String args[])
{
Scanner scr=new Scanner(System.in);
System.out.println("Enter the number of page entries");
int n=scr.nextInt();
int fault=0,hit=0;
int p[]=new int[n];
System.out.println("Enter the pages ");
for(int i=0;i<n;++i)
p[i]=scr.nextInt();
System.out.print("The page table entries are ");
for(int i=0;i<n;++i)
System.out.print(" "+p[i]);
System.out.println();
int s=3;
System.out.println("Do you wish to set a the number of page frames?(1=yes/0=no)");
int ch=scr.nextInt();

if(ch==1)
 {
 System.out.println("Enter the number of page frames ");
 s=scr.nextInt();
 System.out.println("The number of page frames set to "+s);
 }
else
 System.out.println("The default number of page frames are "+s);

int pf[]=new int[s];
for(int i=0;i<s;++i)
pf[i]=-1;
int d=0;

for(int i=0;i<n;++i)
{
if(check(pf,s,p[i]))
{
++hit;
for(int j=0;j<s && pf[j]!=-1;++j)
System.out.print(pf[j]+" ");
System.out.print("H\n");
}
else
{
++fault;
if(d>s-1)
d=0;
pf[d]=p[i];
++d;
for(int j=0;j<s && pf[j]!=-1;++j)
System.out.print(pf[j]+" ");
System.out.print("F\n");
}
}
System.out.println("Number of page Hits= "+hit+"\nNumber of page Faults= "+fault);
}
}

Sem 4 Operating System (OS) : Round Robin process scheduling Java Code / Program

Given below is the Java code for Round Robin Process Scheduling algorithm.

import java.util.*;
class Process
{
Scanner scr=new Scanner(System.in);
int p[];
int bt,tt,wt;
Process(int i)
{
System.out.println("Enter the burst time of process "+(i+1));
bt=scr.nextInt();
}
}
class RR1
{
static boolean check(Process p[],int n)
{
int s=0;
for(int i=0;i<n;++i)
s+=p[i].bt;
if(s<=0)
return false;
else
return true;
}
public static void main(String args[])
{
Scanner scr=new Scanner(System.in);
System.out.println("Enter the number of processes");
int n =scr.nextInt();
Process p[]=new Process[n];
for(int i=0;i<n;++i)
p[i]=new Process(i);
System.out.println("The quantum size is 5 ms ");
int burst[]=new int[n];

for(int i=0;i<n;++i)
burst[i]=p[i].bt;
for(int i=0;i<n;++i)
System.out.println("The  burst time of process "+(i+1)+" is "+burst[i]);
int time=0;
int temp;
int flag[]=new int[n];
for(int i=0;i<n;++i)
flag[i]=0;
do
{

loop:for(int k=0;k<n;++k)
{
//System.out.println(" Flag value is "+flag[k]);
if(flag[k]==0)
{
temp=p[k].bt;
if(p[k].bt>5)
{
p[k].bt-=5;
time+=5;
//System.out.println("The time value "+time);
}
else
{
p[k].bt=0;
time+=temp;
p[k].tt=time;
flag[k]=1;
//System.out.println("The process "+(k+1)+" ends");
//System.out.println("flag value "+flag[k]);
}
}
else continue loop;
}
}
while(check(p,n)); 
for(int i=0;i<n;++i)
p[i].wt=p[i].tt-burst[i];
double s1=0,s2=0;
for(int i=0;i<n;++i)
{
System.out.println("The turn around time of process "+(i+1)+" is "+p[i].tt);
System.out.println("The wait time of process "+(i+1)+" is "+p[i].wt);
}
for(int i=0;i<n;++i)
s1+=p[i].tt;
for(int i=0;i<n;++i)
s2+=p[i].wt;
double att=0,awt=0;
att=s1/n;
awt=s2/n;
System.out.println("The average turn around time is "+att+"\nThe average wait time is "+awt);
}
}
/* Output
Enter the number of processes
4
Enter the burst time of process 1
12
Enter the burst time of process 2
3
Enter the burst time of process 3
7
Enter the burst time of process 4
15
The quantum size is 5 ms
The  burst time of process 1 is 12
The  burst time of process 2 is 3
The  burst time of process 3 is 7
The  burst time of process 4 is 15
The turn around time of process 1 is 32
The wait time of process 1 is 20
The turn around time of process 2 is 8
The wait time of process 2 is 5
The turn around time of process 3 is 25
The wait time of process 3 is 18
The turn around time of process 4 is 37
The wait time of process 4 is 22
The average turn around time is 25.5
The average wait time is 16.25      */

Saturday, 28 January 2012

Sem 4 Operating System : Process scheduling Algorithm - Pre-emptive Priority Algorithm Java program / code

Given below is Java program for Pre-emptive Priority algorithm.

//Aim:To implement preemptive priority scheduling   
//Program:
import java.util.*;
class PR
{
public int bt;
public int at;
public int pt;
public int pr;
PR()
{
bt=0;
at=0;
pt=0;
}
PR(int x,int y,int z)
{
bt=x;
at=y;
pt=z;
}
void t(PR p2)
{
pr=p2.at-at;
}
}
class PEP
{
static int sum(PR p[],int n)
{
int s=0;
for(int i=0;i<n;++i)
s+=p[i].bt;
if(s==0)
return 1;
else
return 0;
}
public static void main(String args[])
{
PR p[];
Scanner scr=new Scanner(System.in);
System.out.println("Enter the number of processes");
int n=scr.nextInt();
p=new PR[n];
int i=0,j=0;
int bt,at,pt;
for(i=0;i<n;++i)
{
System.out.println("Enter the burst time and arrival time & priority of a process");
bt=scr.nextInt();
at=scr.nextInt();
pt=scr.nextInt();
p[i]=new PR(bt,at,pt);
}
PR temp;
//  Sorting processes in increasing order of arrival time
for(i=0;i<=n-2;++i)
{
for(j=i;j<=n-1;++j)
{
if(p[i].at>p[j].at)
{
temp=p[i];
p[i]=p[j];
p[j]=temp;
}
}
}
int tt[]=new int[n];
int wt[]=new int[n];
int b[]=new int[n];
for(i=0;i<n;++i)
b[i]=p[i].bt;
for(i=0;i<n;++i)
{
System.out.println("Process "+(i+1)+" Burst time= "+p[i].bt+" priority= "+p[i].pt+" Arrival time= "+p[i].at);
}
int time=0;
int av;
for(int k=0;k<n-1;++k)
{
p[k].t(p[k+1]);
}
System.out.println();
int t1;
do
{
t1=0;
av=0;
for(i=0;i<n;++i)
if(p[i].at<=time)
++av;
int hp;
int max=0;
if(p[0].bt==0)
{
for(i=1;i<n;++i)
if(p[i].bt!=0)
{
max=i;break;
}
}
for(i=0;i<av;++i)
{
if((p[max].pt>p[i].pt) && p[i].bt>0)
max=i;
}
hp=max;
p[hp].bt-=1;
++time;
if(p[hp].bt==0)
tt[hp]=time;
++t1;
}
while(sum(p,n)!=1);
double att=0,awt=0;
double s1=0,s2=0;
for(i=0;i<n;++i)
tt[i]=tt[i]-p[i].at;
System.out.println();
for(int h=0;h<n;++h)
System.out.println("Turn around time of process "+(h+1)+" = "+tt[h]+"  wait time = "+(tt[h]-b[h]));

for(i=0;i<n;++i)
wt[i]=tt[i]-b[i];
for(i=0;i<n;++i)
{
s1+=tt[i];
s2+=wt[i];
}
att=s1/n;
awt=s2/n;
System.out.println("Average Turn around time= "+att+" Average wait time= "+awt);
}
}
/* output
Enter the number of processes
5
Enter the burst time and arrival time & priority of a process
10
0
3
Enter the burst time and arrival time & priority of a process
1
1
1
Enter the burst time and arrival time & priority of a process
2
2
3
Enter the burst time and arrival time & priority of a process
1
3
4
Enter the burst time and arrival time & priority of a process
5
4
2
Process 1 Burst time= 10 priority= 3 Arrival time= 0
Process 2 Burst time= 1 priority= 1 Arrival time= 1
Process 3 Burst time= 2 priority= 3 Arrival time= 2
Process 4 Burst time= 1 priority= 4 Arrival time= 3
Process 5 Burst time= 5 priority= 2 Arrival time= 4
Turn around time of process 1 = 16  wait time = 6
Turn around time of process 2 = 1  wait time = 0
Turn around time of process 3 = 16  wait time = 14
Turn around time of process 4 = 16  wait time = 15
Turn around time of process 5 = 5  wait time = 0
Average Turn around time= 10.8 Average wait time= 7.0          */

Wednesday, 25 January 2012

Sem 4 (AOAD) : Graph traversal Techniques- Breadth First Search (BFS) & Depth First Search (DFS) Java program / code.

Given below are java codes for graph traversal techniques.

Breadth First Search Java Code

// Aim:To implement Breadth first search  
import java.util.*;
class Graph
{
Scanner scr=new Scanner(System.in);
static int a[][];
static int visit[]=new int[10];
void adjm(int v,int e)
{
a=new int[v+1][v+1];
for(int i=1;i<=v;++i)
{
for(int j=1;j<=v;++j)
{
a[i][j]=0;
}
}
for(int i=1;i<=e;++i)
{
System.out.println("Enter vertices of edge");
int b=scr.nextInt();
int c=scr.nextInt();
a[b][c]=a[c][b]=1;
}
}
void bft(int v,int e)
{
for(int i=1;i<=v;++i)
{
if(visit[i]==0)
bfs(i,v);
}
}
void bfs(int u,int v)
{
visit[u]=1;
System.out.print(" "+u);
for(int i=1;i<=v;++i)
{
if(a[u][i]==1)
{
if(visit[i]==0)
{
visit[i]=1;
System.out.print(" "+i);
}
}
}
}
void dft()
{
for(int i=1;i<=v;++i)
{
if(visit[i]==0)
dfs(i);
}
}
void dfs(int u)
{
System.out.print(" "+u);
visit[u]=1;
for(int i=1;i<=v;++i)
{
if(a[u][i]==1)
{
if(visit[i]==0)
dfs(i);
}
}
}
}
class GT
{
public static void main(String args[])
{
Scanner scr=new Scanner(System.in);
try
{
System.out.println("Enter v & e");
int v=scr.nextInt();
int e=scr.nextInt();
Graph g=new Graph();
g.adjm(v,e);
g.bft(v,e);
}
catch(Exception e)
{}
}
}
/*  output
Enter v & e
4
4
Enter vertices of edge
1
2
Enter vertices of edge
2
3
Enter vertices of edge
3
4
Enter vertices of edge
1
4
 1 2 4 3       */

Depth First Search Java code

// Aim:To implement Depth first search   
import java.util.*;
class Graph
{
Scanner scr=new Scanner(System.in);
static int a[][];
static int visit[]=new int[10];
static int v,e;
void adjm(int v,int e)
{
a=new int[v+1][v+1];
this.v=v;
this.e=e;
for(int i=1;i<=v;++i)
{
for(int j=1;j<=v;++j)
{
a[i][j]=0;
}
}
for(int i=1;i<=e;++i)
{
System.out.println("Enter vertices of edge");
int b=scr.nextInt();
int c=scr.nextInt();
a[b][c]=a[c][b]=1;
}
}
void dft()
{
for(int i=1;i<=v;++i)
{
if(visit[i]==0)
dfs(i);
}
}
void dfs(int u)
{
System.out.print(" "+u);
visit[u]=1;
for(int i=1;i<=v;++i)
{
if(a[u][i]==1)
{
if(visit[i]==0)
dfs(i);
}
}
}
}
class GT1
{
public static void main(String args[])
{
Scanner scr=new Scanner(System.in);
System.out.println("Enter v & e");
int v=scr.nextInt();
int e=scr.nextInt();
Graph g=new Graph();
g.adjm(v,e);
g.dft();
}
}
/* output
Enter v & e
7
10
Enter vertices of edge
1
4
Enter vertices of edge
4
7
Enter vertices of edge
4
6
Enter vertices of edge
1
2
Enter vertices of edge
2
3
Enter vertices of edge
2
5
Enter vertices of edge
3
5
Enter vertices of edge
1
5
Enter vertices of edge
1
6
Enter vertices of edge
5
6
 1 2 3 5 6 4 7    */

Friday, 20 January 2012

Semester 3:Data Structures and Files (DSF) Java programs for searching, sorting, Stack, Linked List, Queue free download.

For Stack , Queue, Linked list, Searching, Sorting programs, use the 'Download Box' in the blog to download the file 'dsf.rar'.