CareerCup

take care of overflow and underflow condition by checking front and rear pointers

Stupid question...and same the answers...How can you check if an array is circular??
The question is asking for a queue using an array and you all implement it using linked list, why?

1. Keep adding elements to the array/Queue until its full

[1,4,6,7] front =0, rear=3

2. When full, delete one element and add a new element

[4,6,7,8(this is the 0th index if circular)] front =1, rear=0

3. If now, the rear index < front index, Queue is circular

rear =0 < front =1

{
good
}

For Circular Queue

Have 2 pointers rear and front.
count=no of elements
For Insertion :
rear = (rear + 1) mod capacity
count++

For Deletion
front = (front+1) mode capacity
count--

wonderful ! @ Anon
have some

take care of overflow and underflow condition by checking front and rear pointers

//queue using array
#include<stdio.h>
#include<conio.h>
#include<stdlib.h>
#define SIZE 5
int i,rear,front,item,s[SIZE];
void insert(int item,int s[]);
void del(int s[]);
void display(int s[]);
void main()
{
int ch;
clrscr();

front=0;
rear=-1;
do
{
printf("\n\n 1.INSERTION \n 2.DELETION \n 3.EXIT \n");
printf("\nENTER YOUR CHOICE : ");
scanf("%d",&ch);
switch(ch)
{
case 1:
printf("\n\t INSERTION \n");
if(rear>=SIZE-1)
{
printf("\t\nQUEUE IS FULL\n");
}
else
{
printf("\nENTER AN ELEMENT : ");
scanf("%d",&item);
insert(item,s);
}
display(s);
break;
case 2:
printf("\n\t DELETION \n");
if(front>rear)
{
printf("\t\nQUEUE IS EMPTY\n");
}
else
{
del(s);
}
display(s);
break;
}
}while(ch!=3);
getch();
}
void insert(int item,int s[])
{
if(rear<SIZE)
{
rear=rear+1;
s[rear]=item;
}
}
void del(int s[])
{
int i;
item=s[front];
for(i=0;i<=rear;i++)
s[i]=s[i+1];
rear--;
printf("\n DELETED ELEMENT IS %d\n\n",item);
}

void display(int s[])
{
printf("\n");
for(i=front;i<=rear;i++)
{
printf(" \t %d",s[i]);
}
}