CPU Scheduling Algorithm - FCFS

This is a C program which implements one of the CPU Scheduling algorithm called First Come First Served(FCFS). FCFS is the simplest scheduling algorithm , easy to understand and implement but not as efficient as remaining scheduling algorithms as its waiting time is high. As the name suggests , here the processes/jobs are executed on first come first serve basis.

PROGRAM :

#include <stdio.h>
#include <stdlib.h>

int main()
{
    int i,n,bt[1000],wt[1000];
    float avgWt,totalWt=0;
    printf("Enter how many jobs ?\t");
    scanf("%d",&n);
    for(i=0;i<n;i++)
    {
        printf("Enter burst time for job %d :\t",i+1);
            scanf("%d",&bt[i]);
    }
    printf("\n\nWaiting time for Job 1 : 0 units\t");
        wt[0]=0;
    for(i=1;i<n;i++)
    {
        wt[i]=bt[i-1]+wt[i-1];
        printf("\nWaiting time for Job %d : %d units \t",i+1,wt[i]);
            totalWt = totalWt + wt[i];
    }
    printf("\n\nThe total waiting time : %f\t",totalWt);
    avgWt= totalWt/n;
    printf("\n\nAverage waiting time : %f\t\n\n",avgWt);
    return 0;
}

NOTE : Assuming that all the jobs arrive at the same time.


OUTPUT :

C - CPU Scheduling Algorithm(FCFS)