Most Important Data Structure Interview Questions Part – 3

1.What is data structure?

A data structure is a way of organizing data that considers not only the items stored,but also their relationship to each other. Advance knowledge about the relationship between data items allows designing of efficient algorithms for the manipulation of data.

2.Minimum number of queues needed to implement the priority queue?

Two. One queue is used for actual storing of data and another for storing priorities.

3.What are the notations used in Evaluation of Arithmetic Expressions using prefix and postfix forms?

Polish and Reverse Polish notations.

4.List out few of the Application of tree data-structure?

i)The manipulation of Arithmetic expression
ii)Symbol Table construction
iii)Syntax analysis.

5.What is the type of the algorithm used in solving the 8 Queens problem?

Backtracking

6.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.

7.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.

8.List out the areas in which data structures are applied extensively

Compiler Design,Operating System,Database Management System,Statistical analysis package,Numerical Analysis,Graphics,Artificial Intelligence,Simulation

9.Translate infix expression into its equivalent post fix expression: (A-B)*(D/E)

(A-B)*(D/E) = [AB-]*[DE/] = AB-DE/*

10.What are priority queues?

A priority queue is a collection of elements such that each element has been assigned a priority.

11.What is a string?

A sequential array of characters is called a string.

12.What is Brute Force algorithm?

Algorithm used to search the contents by comparing each element of array is called Brute Force algorithm.

13.What are the limitations of arrays?

i)Arrays are of fixed size.
ii)Data elements are stored in continuous memory locations which may not be available always.
iii)Adding and removing of elements is problematic because of shifting the locations.

14.How can you overcome the limitations of arrays?

Limitations of arrays can be solved by using the linked list.

15.What is a linked list?

Linked list is a data structure which store same kind of data elements but not in continuous memory locations and size is not fixed. The linked lists are related logically.

16.What is a node?

The data element of a linked list is called a node.

17.What does node consist of?

Node consists of two fields:data field to store the element and link field to store the address of the next node.

18.What is a queue ?

A Queue is a sequential organization of data. A queue is a first in first out type of data structure. An element is inserted at the last position and an element is always taken out from the first position.

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

Open addressing (closed hashing),The methods used include:Overflow block
Closed addressing (open hashing),The methods used include:Linked list,Binary tree

20.What are the methods available in storing sequential files ?

Straight merging,Natural merging,Polyphase sort,Distribution of Initial runs.

21.Mention some of the problem solving strategies?

The most widely strategies are listed below

i)Divide and conquer
ii)Binary doubling strategy
iii)Dynamic programming

22.What is divide and conquer method?

The basic idea is to divide the problem into several sub problems beyond which cannot be further subdivided. Then solve the sub problems efficiently and join then together to get the solution for the main problem.

23.What is the need for the header?

Header of the linked list is the first element in the list and it stores the number of elements in the list. It points to the first data element of the list.

24.Define leaf

In a directed tree any node which has out degree o is called a terminal node or a leaf.

25.What are the applications of binary tree?

Binary tree is used in data processing.

26.What are the different types of traversing?

The different types of traversing are

i)Pre-order traversal-yields prefix from of expression.
ii)In-order traversal-yields infix form of expression.
iii)Post-order traversal-yields postfix from of expression.

27.Define pre-order traversal

i)Process the root node
ii)Process the left subtree
iii)Process the right subtree

28.Define post-order traversal

i)Process the left subtree
ii)Process the right subtree
iii)Process the root node