Functions for inserting and deleting at either of the end, Data Structure & Algorithms

Assignment Help:

Q. Develop a representation for a list where insertions and deletions can be done at either end. Such a structure is known as a Deque (Double ended queue). Write functions for inserting and deleting at either of the end.

Ans.

There are number of ways of representing dequeue in a computer. We will suppose that dequeue is maintained by a circular array DEQUE with pointer FRONT and REAR, which point to the 2 ends of dequeue. We suppose that the element extend from the left end to the right end in the array. The condition FRONT = NULL will be used to indicate that dequeue is blank.

Algorithm for inserting in dequeue is written below

Step 1:  [check overflow condition] If rear ≥  n and front = 0

Output :overflow and return"

Step 2:  [check front pointer value] If front > 0

Front = front -1

Else

Return

Step 3:  [insert element at the front end] Q[front ] = value

Step 4:  [check rear pointer value] If rear < n

Rear = rear +1

Else

Return

Step 5:  [insert element at the rear end] Q [rear] = value

Step 6:  Return

Deletion Algorithm for dequeue is given below

Step 1:  [check for underflow] If front = 0 and rear = 0

Output "underflow" and return

Step 2:  [delete element at front end] If front > 0

Value = q [front] Return [value]

Step 3:  [check queue for empty]

If front = rear

Front = rear = 0

Else

Front = front +1

Step 4:  [delete element at the rear end] If rear > 0

Value = Q [rear] Return (rear)

Step 5:  [check queue for empty] If front = rear

Front = rear = 0

Else

Rear = rear - 1

Step 6:   Return


Related Discussions:- Functions for inserting and deleting at either of the end

Explain circular queues, Circular Queues:- A more efficient queue repre...

Circular Queues:- A more efficient queue representation is get by regarding the array Q(1:n) as circular. It becomes more convenient to declare the array as Q(O: n-1), when  re

Explain multiplication method, Multiplication Method: The multiplication m...

Multiplication Method: The multiplication method operates in 2 steps. In the 1ststep the key value K is multiplied by a constant A in the range O

Hashing and collisions during hashing, Q. What do you understand by the te...

Q. What do you understand by the term Hashing?  How do the collisions occur during hashing?  Explain the different techniques or methods for resolving the collision.

Graph connectivity, A connected graph is a graph wherein path exists among ...

A connected graph is a graph wherein path exists among every pair of vertices. A strongly connected graph is a directed graph wherein every pair of distinct vertices is connecte

The space - time trade off, The best algorithm to solve a given problem is ...

The best algorithm to solve a given problem is one that requires less space in memory and takes less time to complete its execution. But in practice it is not always possible to

Explain the scan-line algorithm, Explain the Scan-Line Algorithm This i...

Explain the Scan-Line Algorithm This image-space method for removing hidden surfaces is an extension of the scan-line algorithm for filling polygon interiors. Instead of fillin

Collision resolution techniques, complete information about collision resol...

complete information about collision resolution techniques

Reverse order of elements on a slack, Q. Reverse the order of the elements ...

Q. Reverse the order of the elements on a stack S    (i) by using two additional stacks (ii) by using one additional queue. Ans :      L e t S be the stac

Depth First Search Through Un-weighted Connected Graph , Q. Write down the ...

Q. Write down the algorithm which does depth first search through an un-weighted connected graph. In an un-weighted graph, would breadth first search or depth first search or neith

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd