Question

A limited-sized Queue ADT is an abstract data type that has a limit on the length of the queue. It can be created with a static array of size N, where N is the maximum length of the array. In C, this structure can be defined as follows: typedef struct {int * data;//array of the data on the queue//you may add other attributes here but use as few as possible} queue_t; Write an (efficient) pseudocode for the implementation of each of the following function prototypes (proper C code will also be accepted) void print (Q) - prints the entire queue Q from front to back. int enqueue (Q, x) - enqueues the element x into queue Q(if unsuccessful, return-1) int* dequeue (Q) - dequeues the next integer from front of the queue (if unsuccessful, return null) int isEmpty(Q) - returns 1 (true) or 0 (false) depending on emptiness of the queue Q unsigned int size(Q) - returns the number of items currently in the queue. In your final solution, you may add any extra attributes that you feel is needed for this question but you must use as few extra attributes as possible and your algorithm must be as efficient as possible (in terms of big-O analysis).

Answer 1

#include<conio.h>
#include<stdio.h>
#define max 5
int queue[max],front=0,rear=0;
int menu();
void enqueue();
void dequeue();
void display();
void isempty();
void size_();
void main()
{
int ch;
printf("\nQueues using Arrays\n");
do
{
ch=menu();
switch(ch)
{
case 1: enqueue();
break;
case 2: dequeue();
break;
case 3: display();
break;
case 4: isempty();
break;
case 5: size_();
break;
default:printf("\n Please enter a valid choice!!");
}
}while(1);
}

int menu()
{
int ch;
printf("\n1.ENQUEUE \n2.DEQUEUE \n3.DISPLAY \n4.isempty \n5.size \n");
printf("\nEnter your Choice:");
scanf("%d",&ch);
return ch;
}

void enqueue()
{
int element;
if(rear==max)
{
printf("\nOverflow!!");
}
else
{
printf("\nEnter Element:");
scanf("%d",&element);
queue[rear++]=element;
printf("\n %d Enqueued at %d",element,rear);
}

}

void dequeue()
{
if(rear==front)
{
printf("\nUnderflow!!");
}
else
{
front++;
printf("\nElement is Dequeued from %d",front);
}
}
void display()
{
int i;
if(front==rear)
{
printf("\nQueue is Empty!!!");
}
else
{
printf(" \n");
for(i=front;i<max;i++)
{
printf(" | %d ",queue[i]);
}
printf("|");
}
}
void isempty()
{
if(front==rear)
printf("THE QUEUE IS EMPTY \n");
}

void size_()
{
int count=0,i;
if(rear==1)
count=1;
else if(front==rear)
count=0;
else{
for(i=front;i<=rear;i++)
count=count+1;}
printf("%d\n",count);
}

OUTPUT:

Queues using Arrays 1. ENQUEUE 2. DEQUEUE 3.DISPLAY 4. isempty 5.size Enter your choice:5 1. ENQUEUE 2. DEQUEUE 3.DISPLAY 4. isempty 5.size Enter your Choice 1 Enter Element:2

2 Enqueued at 1 1.ENQUEUE 2. DEQUEUE 3.DISPLAY 4. isempty 5.size nter your Choice:1 Enter Element: 4 4 Enqueued at 2 1.ENQUEUE 2. DEQUEUE 3.DISPLAY 4. isempty 5.size Enter your Choice:2 Element is Dequeued from 1

1. ENQUEUE 2. DEQUEUE 3. DISPLAY H.isempty 5.size Enter your Choice:2 Element is Dequeued from2 1. ENQUEUE 2. DEQUEUE 3.DISPLAY 4.isempty 5.size Enter your Choice: 4 THE QUEUE IS EMPTY