Write the program to simulate Non-preemptive Shortest Job First (SJF) -scheduling.

Write the program to simulate Non-preemptive Shortest Job First (SJF) -scheduling. The
arrival time and first CPU-burst for different n number of processes should be input to
the algorithm. Assume the fixed IO waiting time (2 units). The next CPU-burst should be
generated randomly. The output should give Gantt chart, turnaround time and waiting
time for each process. Also find the average waiting time and turnaround time.

 #include<stdio.h>
#include<string.h>
#include<stdlib.h>
typedef struct SJF
{
char name[20];
int at,bt,ct,tbt,wt,tat;
}SJF;
SJF* s;
int n,currenttime,cnt;
float totalwt,totaltat,avgwt,avgtat;


void accept()
{
int i;
printf("Enter no of processes ");
scanf("%d",&n);
s=(SJF*)malloc(sizeof(SJF)*n);

for(i=0;i<n;i++)
{
printf("Enter process name ");
scanf("%s",&s[i].name);
printf("Enter arrival time ");
scanf("%d",&s[i].at);
printf("Enter burst time ");
scanf("%d",&s[i].bt);
s[i].tbt=s[i].bt;
}
}


void sort()
{
SJF t;
int i,j;

for(i=0;i<n;i++)
for(j=i+1;j<n;j++)
if(s[i].at>s[j].at)
{
t=s[i];
s[i]=s[j];
s[j]=t;
}

}


int getindex()
{
int i,loc=-1,min=999;
for(i=0;i<n;i++)
if(s[i].tbt!=0 && s[i].at<=currenttime)
{
if(s[i].bt<min)
{
min=s[i].bt;
loc=i;
}
}
return loc;
}


void sechedule()
{
int i;
sort();
printf("\n********************************Gantt Chart********************************\n");
while(1)
{
i=getindex();
if(i==-1)
{
printf("|%d idel",currenttime);
currenttime=s[cnt].at;
printf("%d",currenttime);
}
else
{
printf("|%d %s ",currenttime,s[i].name);
s[i].wt=currenttime-s[i].at;
s[i].tat=s[i].wt+s[i].bt;
s[i].tbt=0;
currenttime+=s[i].bt;
s[i].ct=currenttime;
printf("%d",currenttime);
totalwt+=s[i].wt;
totaltat+=s[i].tat;


cnt++;
if(cnt==n)
break;
}
}
avgwt=totalwt/n;
avgtat=totaltat/n;
}


void display()
{
int i;
printf("\n***************************************************************************\n");
printf("\nName\tArrival Time\tBurst Time\tWaiting Time\tTurn Around Time\n");
for(i=0;i<n;i++)
printf("%s\t%d\t\t%d\t\t%d\t\t%d\n",s[i].name,s[i].at,s[i].bt,s[i].wt,s[i].tat);
printf("\nTotal waiting time %f",totalwt);
printf("\nTotal Turn Around time %f",totaltat);
printf("\nAverage waiting time %f",avgwt);
printf("\nAverage Turn Around time %f\n",avgtat);
}


main()
{
accept();
sechedule();
display();
}