DATA STRUCTURES APTITUDE

•             Classify the Hashing Functions based on the various methods by which the key value is found.

Ø  Direct method,

Ø  Subtraction method,

Ø  Modulo-Division method,

Ø  Digit-Extraction method,

Ø  Mid-Square method,

Ø  Folding method,

Ø  Pseudo-random method.  

•           What are the types of Collision Resolution Techniques and the methods used in each of the type?

Ø  Open addressing (closed hashing),

The methods used include:

                        Overflow block,

Ø  Closed addressing (open hashing)

The methods used include:

Linked list,

Binary tree…

•         In RDBMS, what is the efficient data structure used in the internal storage representation?

            B+ tree. Because in B+ tree, all the data is stored only in leaf nodes, that makes searching easier. This corresponds to the records that shall be stored in leaf nodes.    

•       Of the following tree structure, which is, efficient considering space and time complexities?

(a)   Incomplete Binary Tree

(b)   Complete Binary Tree     

(c)    Full Binary Tree

            (b) Complete Binary Tree.

By the method of elimination:

Full binary tree loses its nature when operations of insertions and deletions are done. For incomplete binary trees, extra storage is required and overhead of NULL node checking takes place. So complete binary tree is the better one since the property of complete binary tree is maintained even after operations like additions and deletions are done on it. 

•              What is a spanning Tree?

            A spanning tree is a tree associated with a network. All the nodes of the graph appear on the tree once. A minimum spanning tree is a spanning tree organized so that the total edge weight between nodes is minimized.

•              Does the minimum spanning tree of a graph give the shortest distance between any 2 specified nodes?

            No.

            Minimal spanning tree assures that the total weight of the tree is kept at its minimum. But it doesn’t mean that the distance between any two nodes involved in the minimum-spanning tree is minimum.

•           Which is the simplest file structure?

(a)   Sequential

(b)   Indexed

(c)    Random

(a) Sequential

•             Whether Linked List is linear or Non-linear data structure?

            According to Access strategies Linked list is a linear one.

            According to Storage Linked List is a Non-linear one.