2. SJF SCHEDULING IN JAVA

Code:
import java.util.*;
class SJF
{
public static void main(String args[])
{
Scanner sc=new Scanner(System.in);
int pno[]=new int[10];
int bt[]=new int[10];
int wt[]=new int[10];
int tt[]=new int[10];
int tempwt[]=new int[10];
int tempno[]=new int[12];//stores process no temporary
int temp[]=new int[12];//represent Gantt chart
int n,i,j,ptr,t,t2;

float awt,atat,twt=0,ttat=0;
System.out.println("Enter no of processes(less than 10):");
n=sc.nextInt();
for(i=0;i<n;i++)
{
System.out.println("Enter the burst time of process "+(i+1));
bt[i]=sc.nextInt();
temp[i]=bt[i];
pno[i]=i+1;
tempno[i]=pno[i];
}
for(i=0;i<n;i++)
{
ptr=0;
while(ptr<=n-i)
{
if(temp[ptr]>temp[ptr+1])
{
t=temp[ptr];
temp[ptr]=temp[ptr+1];
temp[ptr+1]=t;
t2=tempno[ptr];
tempno[ptr]=tempno[ptr+1];
tempno[ptr+1]=t2;
}
ptr++;
}
}
for(i=0;i<n;i++)
{
temp[i]=temp[i+2];
tempno[i]=tempno[i+2];
}
tempwt[0]=0;
for(i=1;i<n;i++)
tempwt[i]=tempwt[i-1]+temp[i-1];
for(i=0;i<n;i++)
{
j=0;
while(tempno[i]!=pno[j]&&j<n)
j++;
wt[j]=tempwt[i];
}
for(i=0;i<n;i++)
tt[i]=wt[i]+bt[i];
for(i=0;i<n;i++)
{
twt=twt+wt[i];
ttat=ttat+tt[i];
}
awt=twt/n;
atat=ttat/n;
System.out.println("Process\tBurst Time\tWaiting Time\tTurnaround Time");
for(i=0;i<n;i++)
{
System.out.print("P"+pno[i]+"\t"+bt[i]+"\t\t"+wt[i]+"\t\t"+tt[i]);
System.out.println();
}
System.out.println("Average Waiting Time="+awt);
System.out.println("Average Turnaround Time="+atat);
}
}


OUTPUT:

Enter no of processes(less than 10):
5
Enter the burst time of process 1
10
Enter the burst time of process 2
1
Enter the burst time of process 3
2
Enter the burst time of process 4
1
Enter the burst time of process 5
5
Process Burst Time Waiting Time Turnaround Time
P1          10           9            19
P2           1           0             1
P3           2           2             4
P4           1           1             2
P5           5           4             9
Average Waiting Time=3.2
Average Turnaround Time=7.0