os SJF scheduling algorithms in c code example
Example 1: os SJF scheduling algorithms in c
int main()
{
int bt[20],p[20],wt[20],tat[20],i,j,n,total=0,pos,temp;
float avg_wt,avg_tat;
printf("Enter number of process:");
scanf("%d",&n);
printf("nEnter Burst Time:n");
for(i=0;i<n;i++)
{
printf("p%d:",i+1);
scanf("%d",&bt[i]);
p[i]=i+1;
}
//sorting of burst times
for(i=0;i<n;i++)
{
pos=i;
for(j=i+1;j<n;j++)
{
if(bt[j]<bt[pos])
pos=j;
}
temp=bt[i];
bt[i]=bt[pos];
bt[pos]=temp;
temp=p[i];
p[i]=p[pos];
p[pos]=temp;
}
wt[0]=0;
for(i=1;i<n;i++)
{
wt[i]=0;
for(j=0;j<i;j++)
wt[i]+=bt[j];
total+=wt[i];
}
avg_wt=(float)total/n;
total=0;
printf("nProcesst Burst Time tWaiting TimetTurnaround Time");
for(i=0;i<n;i++)
{
tat[i]=bt[i]+wt[i];
total+=tat[i];
printf("np%dtt %dtt %dttt%d",p[i],bt[i],wt[i],tat[i]);
}
avg_tat=(float)total/n;
printf("nnAverage Waiting Time=%f",avg_wt);
printf("nAverage Turnaround Time=%fn",avg_tat);
}
Example 2: scheduling algorithm os c code
int main()
{
int arrival_time[10], burst_time[10], temp[10];
int i, smallest, count = 0, time, limit;
double wait_time = 0, turnaround_time = 0, end;
float average_waiting_time, average_turnaround_time;
printf("nEnter the Total Number of Processes:t");
scanf("%d", &limit);
printf("nEnter Details of %d Processesn", limit);
for(i = 0; i < limit; i++)
{
printf("nEnter Arrival Time:t");
scanf("%d", &arrival_time[i]);
printf("Enter Burst Time:t");
scanf("%d", &burst_time[i]);
temp[i] = burst_time[i];
}
burst_time[9] = 9999;
for(time = 0; count != limit; time++)
{
smallest = 9;
for(i = 0; i < limit; i++)
{
if(arrival_time[i] <= time && burst_time[i] < burst_time[smallest] && burst_time[i] > 0)
{
smallest = i;
}
}
burst_time[smallest]--;
if(burst_time[smallest] == 0)
{
count++;
end = time + 1;
wait_time = wait_time + end - arrival_time[smallest] - temp[smallest];
turnaround_time = turnaround_time + end - arrival_time[smallest];
}
}
average_waiting_time = wait_time / limit;
average_turnaround_time = turnaround_time / limit;
printf("nnAverage Waiting Time:t%lfn", average_waiting_time);
printf("Average Turnaround Time:t%lfn", average_turnaround_time);
return 0;
}