fcfs.cpp

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


typedef struct process
{
	int id,at,bt,st,ft,pr;
	float wt,tat;
}process;

process p[10],p1[10],temp;

int accept();
void turnwait(int n);
void display(int n);
void ganttfcfs(int n);

int main()
{
	int i,n,ts,ch,j,x;
	p[0].tat=0;
	p[0].wt=0;
	n=accept();
	ganttfcfs(n);
	turnwait(n);
	display(n);
	return 0;
}

int accept()  //functions for accepting inputs from the user
{
	int i,n;
	printf("\nEnter the no. of process: ");
	scanf("%d",&n);
	if(n==0)
	{
		printf("\nInvalid no. of process");
		exit(1);
	}
	for(i=1;i<=n;i++)
	{
		printf("\nEnter the arrival time for process P%d: ",i);
		scanf("%d",&p[i].at);
		p[i].id=i;
	}
	for(i=1;i<=n;i++)
	{
		printf("\nEnter the burst time for process P%d: ",i);
		scanf("%d",&p[i].bt);
	}
	printf("\nInputs given by the user are:\n");
	printf("==============================================================");
	printf("\nProcess\tAT\tBT");
	for(i=1;i<=n;i++)
		printf("\nP%d\t%d\t%d",p[i].id,p[i].at,p[i].bt);
	printf("\n============================================================");	
	for(i=1;i<=n;i++)	// copying of one array into another array(dummy area)
		p1[i]=p[i];
	return n;
}
/*FUNCTION FOR DISPLAYING GANTT CHART FOR FIRST COME FIRST SERVE SCHEDULING*/
void ganttfcfs(int n)
{
	int i;
	p[1].st=p[1].at;	
	for(i=2;i<=n;i++)
		p[i].st=p[i-1].st+p[i-1].bt;
	p[1].ft=p[1].bt;
	for(i=2;i<=n;i++)
		p[i].ft=p[i-1].ft+p[i].bt;
	printf("\nGant Chart is as follows:\n\n");
	printf("%d->P%d->%d",p[1].st,p[1].id,p[1].ft);
	for(i=2;i<=n;i++)
		printf("->P%d->%d",p[i].id,p[i].ft);
	printf("\n");
}

/* FUNCTION FOR CALCULATING TURN AROUND TIME OR WAIT TIME */
void turnwait(int n)
{
	int i;	
	for(i=1;i<=n;i++)
	{
		p[i].tat=p[i].ft-p[i].at;
		p[i].wt=p[i].tat-p[i].bt;
		p[0].tat=p[0].tat+p[i].tat;
		p[0].wt=p[0].wt+p[i].wt;
	}			
	p[0].tat=p[0].tat/n;
	p[0].wt=p[0].wt/n;
}
/* FUNCTION FOR DISPLAYING THE TABLE */
void display(int n)
{
	int i;	
	printf("\n\n-------------------TABLE----------------------------------\n");
	printf("\nProcess\tAT\tBT\tFT\tTAT\t\tWT");
	for(i=1;i<=n;i++)
		printf("\nP%d\t%d\t%d\t%d\t%f\t%f",p[i].id,p[i].at,p[i].bt,p[i].ft,p[i].tat,p[i].wt);
	printf("\n\n-----------------------------------------------------------");
	printf("\nAverage Turn Around Time: %f",p[0].tat);
	printf("\nAverage Waiting Time: %f",p[0].wt);
	int x;
	scanf("%d",&x);
}