what is Dequeue in data structure
A de-queue is kind of queue in which elements can be added or removed from the either end but not from the middle . the term de-queue is taken from double ended Q.
There are two types of de-queue
-
Input restricted de-queue —
this queue allows insertion only at one end but allow deletion at both ends .
-
Output restricted de-queue —
This queue allow insertion at both ends but deletions only at one end.
Step1 [check for under flow condition]
if front = -1 & rear = -1, then
output underflow & exit
Step2 [delete element at the front end ]
if [front] >= 0 then
then =Q[front]
Step3 [check queue for empty]
if front = rear, then
rear = -1
front = -1
else
front = front+1
Step4 [delete element at the rear end ]
if rear > = 0
item = Q[rear]
Step5 [check queue for empty ]
if front = rear, then
front = -1
rear = -1
else
rear = rear – 1
Step6 exit
Step1 [check for overflow condition]
If front = 0 & rear >= size -1
Output over flow & exit
Step2 : [check front pointer value]
If front >0, then
Front = front -1
Step3: [insert element at the front end ]
Q[front] = value
Step4 : [ check rear pointer value]
If rear < size-1
Rear = rear+1
Step5: [ insert element at the rear end]
Q[rear] = value
Step6 : exit