flight1.c

#include<stdio.h>
#include "flight.h"
void initqueue(struct queue *pq)
{
pq->count=0;
pq->front=0;
pq->rear=-1;
}
void addqueue(struct queue *pq,struct plane item)
{
if(pq->count>=MAX)
{
printf("\nQueue is full.\n");
return;
}
(pq->count)++;
pq->rear=(pq->rear+1)%MAX;
pq->p[pq->rear]=item;
}
struct plane delqueue(struct queue *pq)
{
struct plane pl;
if(pq->count<=0)
{
printf("\nQueue is empty.\n");
pl.id=0;
pl.tm=0;
}
else
{
(pq->count)--;
pl=pq->p[pq->front];
pq->front=(pq->front+1)%MAX;
}
return pl;
}
int size(struct queue q)
{
	return q.count;
}
int empty(struct queue q)
{
	return (q.count<=0);
}
int full(struct queue q)
{
	return(q.count>=MAX);
}
void initairport(struct airport *ap)
{
	initqueue(&(ap->landing));
	initqueue(&(ap->takeoff));
	ap->pl=&(ap->landing);
	ap->pt=&(ap->takeoff);
	ap->nplanes=ap->nland=ap->ntakeoff=ap->nrefuse=0;
	ap->landwait=ap->takeoffwait=ap->idletime=0;
}
void start(int *endtime,double *expectarrive,double *expectdepart)
{
	int flag=0;
	char wish;
	printf("\nProgram that simulates an airport with two runways. \n");
    /*Instruct user*/
    printf("One plane can land or depart in each unit of time.\n");
    printf("Up to %d planes can be waiting to land or take off at any time.\n",MAX);
    printf("How many units of time will the simulation run?");
    /*Input parameter*/
    scanf("%d",endtime);
    myrandomize();
    do
    {
    	printf("\nExpected number of arrivals per unit time"
		    "(real number)?");
    	/*Error checking*/
    	scanf("%lf",expectarrive);
    	printf("\nExpected number of departures per unit time?");
    	scanf("%lf",expectdepart);
    	if(*expectarrive<0.0||*expectdepart<0.0)
    	{
    		printf("These numbers must be nonnegative.\n");
    		flag=0;
		}
		else
			{
				if(*expectarrive+*expectdepart>1.0)   //this program runs properly when (expectarrive+expectdepart)>1
				{
					printf("The airport will become saturated. Read new numbers?");
					fflush(stdin);
					scanf("%c",&wish);
					if(tolower(wish)=='y')
					    flag=0;
					else
					   flag=1;
				}
				else
				   flag=1;

		}
	}while(flag==0);
}
void newplane(struct airport *ap,int curtime,int action)
	/*Newplane:make a new recored for a plane.update nplanes*/
{  //printf("hi");
	(ap->nplanes)++;
	ap->pln.id=ap->nplanes;
	ap->pln.tm=curtime;
	switch(action)
	{
		case ARRIVE:
			printf("\n");
			printf("Plane %d ready to land in Runway 1.\n ",ap->nplanes);
			break;
		case DEPART:
			printf("\n");
			printf("Plane %d ready to takeoff in Runway 2.\n ",ap->nplanes);
			break;
    }
}
void refuse(struct airport *ap,int action)
/*Rfuses processes the plane when queue is full*/
{
	switch(action)
	{
	   case ARRIVE:
			printf("\tPlane %d directed to another airport.\n ",ap->pln.id);
			break;
	   case DEPART:
			printf("\tPlane %d told to try later.\n ",ap->pln.id);
			break;
	}
(ap->nrefuse)++;
}
void land(struct airport *ap,struct plane pl,int curtime)
/*Land :process a plane p that is actually lading in runway 1*/
{
	int wait;
	wait=curtime-pl.tm;
	printf("%d: plane %d landed in Runway 1 ",curtime,pl.id);
	printf("in queue %d units \n",wait);
	(ap->nland++);
	(ap->landwait)+=wait;
}
void fly(struct airport *ap,struct plane pl,int curtime)
/*Fly:process a plane p that is actually landing*/
{
	int wait;
	wait=curtime-pl.tm;
	printf("%d: Plane %d took off",curtime,pl.id);
	printf("in queue %d units \n",wait);
	(ap->ntakeoff)++;
	(ap->takeoffwait)+=wait;
}
void idle(struct airport *ap,int curtime)
/*idle:updates variables for idle runway*/
{
	printf("%d: Runway 1 and 2 is idle.\n",curtime);
	ap->idletime++;
	//printf("idle time : %d",ap->idletime);
}
void conclude(struct airport *ap,int endtime)
/*Conclude:write out statistics and conclude simulation*/
{
	printf("\tSimulation has concluded after %d units.\n",endtime);
	printf("\tTotal number of planes processed:%d\n",ap->nplanes);
	printf("\tNumber of planes landed in Runway 1: %d\n",ap->nland);
	printf("\tNumber of planes taken off in Runway 2: %d\n",ap->ntakeoff);
	printf("\tNumber of planes refused use:%d\n",ap->nrefuse);
	printf("\tNumber left ready to land in Runway 1: %d\n",apsize(*ap,'l'));
	printf("\tNumber left ready to take off in Runway 2: %d\n",apsize(*ap,'t'));
    if(endtime>0)
      printf("\tPercentage of time 2 runways idle: %lf\n",((double)ap->idletime/endtime)*100.0);
    if(ap->nland>0)
      printf("\tAverage wait time to land in Runway 1: %lf\n",((double)ap->landwait/ap->nland));
     if(ap->ntakeoff>0)
      printf("\tAverage wait time to takeoff in Runway 2: %lf\n",((double)ap->takeoffwait/ap->ntakeoff));
}
int randomnumber(double expectedvalue)
/*Randomnumber:generates a pseudorandom integer according to the Poisson distribution*/
{  //printf("x");
	int n=0;  /*Counter of iterations*/
	double em;
	double x;   /*Psuedorandom number*/
	em=exp(-expectedvalue);
	x=rand()/(double)INT_MAX;
	//printf("x: %f / em: %f |",x,em);
	while(x>em)
	{
		n++;
		x*=rand()/(double)INT_MAX;
	}
	//printf("# n:%d #",n);
	return n;
}
void apaddqueue(struct airport *ap,char type)
{
	switch(tolower(type))
	{
	   case 'l':
	      addqueue(ap->pl,ap->pln);
	      break;
	    case 't':
	       addqueue(ap->pt,ap->pln);
	       break;
	}
}
struct plane apdelqueue(struct airport *ap,char type)
{
	struct plane pl;
	switch(tolower(type))
	{
		case 'l':
		   pl=delqueue(ap->pl);
		   break;
		case 't':
			pl=delqueue(ap->pl);
			break;
	}
	return pl;
}
int apsize(struct airport ap,char type)
{
	switch(tolower(type))
	{
		case 'l':
			return(size(*(ap.pl)));
		case 't':
		     return (size(*(ap.pt)));
	}
	return 0;
}
int apfull(struct airport ap,char type)
{
	switch(tolower(type))
	{
		case 'l':
			return(full(*(ap.pl)));
		case 't':
		     return(full(*(ap.pt)));
	}
	return 0;
}
int apempty(struct airport ap,char type)
{
	switch(tolower(type))
	{
		case 'l':
			return(empty(*(ap.pl)));
		case 't':
			return(empty(*(ap.pt)));
	}
	return 0;
}
void myrandomize()
/*Sets starting point for pseudorandam numbers*/
{
	srand((unsigned int)(time(NULL)%10000));
}