6.6 Dequeue

Program Definition
Insert a set of integers into the DEQUEUE ,insert an integer at beginning or at end ,and delete these integers from QUEUE at the beginning or at end .
Algorithm:
INSERTING AT FRONT
1. Declaring the new node.
2. Entering the element into new node.
3. Checking if front= =NULL.
4. Front<- new node.
Front->left <-NULL
Rear<- new node
Rear ->right ->NULL
5. else
new node-> right = front
front <-new node
front<-left <-NULL

ALGORITHM FOR INSERTING
1. Declaring the new node
2. Entering the element into new node.
3. Checking if front = =NULL.
4. front <-new node
front -> left <-NULL
Rear <- new node
Rear -> right<-NULL
5. else
rear = front
temp = front
while temp ->right != NULL
temp <-> temp -> right
rear <- temp
rear ->right <-new node
new node <-left <-rear
rear <-new node
rear ->right <-NULL
ALGORITHM FOR DELETION FROM FRONT
1. Declaring the temporary nodeptr.
2. Check if front = = NULL.
3. Write QUEUE is empty
else
{
if(front = = rear)
{
temp<-rear
temp<-rear
deleting temporary node ptr
front <- rear <-NULL
}
else
{
temp <- front;
current <-front;
temp <-temp <-right;
while(temp ->right !=NULL)
{
temp <-temp ->right
current <-current ->right
}
Rear=temp;
Rear=current;
Delete temporary nodeptr
Rear ->right =NULL
}
}
END


Sample input and output
Output for dequeue
1.ibeg 2.iend 3.dbeg 4.dend 5.display 6.exit
enter u r choice:1
enter the element:2
1.ibeg 2.iend 3.dbeg 4.dend 5.display 6.exit
enter u r choice:1
enter the element:3
1.ibeg 2.iend 3.dbeg 4.dend 5.display 6.exit
enter u r choice:2
enter the data:5
1.ibeg 2.iend 3.dbeg 4.dend 5.display 6.exit
enter u r choice:2
enter the data:6
1.ibeg 2.iend 3.dbeg 4.dend 5.display 6.exit
enter u r choice:5
3 2 5 6

1.ibeg 2.iend 3.dbeg 4.dend 5.display 6.exit
enter u r choice:3
deleted item:3
1.ibeg 2.iend 3.dbeg 4.dend 5.display 6.exit
enter u r choice:4
deleted item:6
1.ibeg 2.iend 3.dbeg 4.dend 5.display 6.exit
enter u r choice:3
deleted item:2
1.ibeg 2.iend 3.dbeg 4.dend 5.display 6.exit
enter u r choice:4
deleted item:5
1.ibeg 2.iend 3.dbeg 4.dend 5.display 6.exit
enter u r choice:5
dq is empty
1.ibeg 2.iend 3.dbeg 4.dend 5.display 6.exit