Program to Implement FCFS Scheduling Algorithm. 
 

#include<stdio.h>
#include<conio.h>
void main()
{
int total ,wt[10],i,ar[10],br[10],fin[10],tr[10];
float t,w;
printf("Enter the no. of processes :");
scanf("%d",&total);
for(i=0;i<total;i++)
{
printf("\nProcess no. %d",i+1);
printf("\nEnter arrival time: ");
scanf("%d",&ar[i]);
printf("Enter burst time : ");
scanf("%d",&br[i]);
}
fin[0]=br[0];
for(i=0;i<total;i++)
{
fin[i+1]=fin[i]+br[i+1];
tr[i]=fin[i]-ar[i];
wt[i]=tr[i]-br[i];
}
printf("\n----------------------------------------------------------------------");
printf("\nPROCESS ARRIVAL BURST FINAL TURNAROUND WAITING");
for(i=0;i<total;i++)
printf("\n%3d%10d%7d%8d%8d%10d",i+1,ar[i],br[i],fin[i],tr[i],wt[i]);
printf("\n----------------------------------------------------------------------");
printf("\nAVERAGE TURNAROUND TIME IN FCFS :");
for(i=0;i<total;i++)
t=t+tr[i];
printf("%f",t/total);
printf("\nAVERAGE WAITING TIME IN FCFS :");
for(i=0;i<total;i++)
w=w+wt[i];
printf("%f",w/total);
getch();
}

Enter the no. of processes :4

Process no. 1
Enter arrival time: 0
Enter burst time : 8

Process no. 2
Enter arrival time: 1
Enter burst time : 4

Process no. 3
Enter arrival time: 2
Enter burst time : 9

Process no. 4
Enter arrival time: 3
Enter burst time : 5

----------------------------------------------------------------------
PROCESS ARRIVAL BURST FINAL TURNAROUND WAITING
1 0 8 8 8 0
2 1 4 12 11 7
3 2 9 21 19 10
4 3 5 26 23 18
----------------------------------------------------------------------
AVERAGE TURNAROUND TIME IN FCFS :15.250000
AVERAGE WAITING TIME IN FCFS :8.750000