1. What is data structure?
Answer: 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. List out the areas in which data structures are applied extensively?
Answer: The name of areas are:
• Compiler Design,
• Operating System,
• Database Management System,
• Statistical analysis package,
• Numerical Analysis,
• Graphics,
• Artificial Intelligence,
• Simulation
3. What are the major data structures used in the following areas : RDBMS, Network data model & Hierarchical data model.
Answer: The major data structures used are as follows:
• RDBMS - Array (i.e. Array of structures)
• Network data model - Graph
• Hierarchical data model - Trees
4. If you are using C language to implement the heterogeneous linked list, what pointer type will you use?
Answer: The heterogeneous linked list contains different data types in its nodes and we need a link, pointer to connect them. It is not possible to use ordinary pointers for this.
So we go for void pointer. Void pointer is capable of storing pointer to any type as it is a generic pointer type.
5. Minimum number of queues needed to implement the priority queue?
Answer: Two. One queue is used for actual storing of data and another for storing priorities.
6. What is the data structures used to perform recursion?
Answer: Stack. Because of its LIFO (Last In First Out) property it remembers its 'caller' so knows whom to return when the function has to return.
Recursion makes use of system stack for storing the return addresses of the function calls.
Every recursive function has its equivalent iterative (non-recursive) function. Even when such equivalent iterative procedures are written,
explicit stack is to be used.
7. What are the notations used in Evaluation of Arithmetic Expressions using prefix and postfix forms?
Answer: Polish and Reverse Polish notations.
8. What is the bucket size, when the overlapping and collision occur at same time?
Answer: One. If there is only one entry possible in the bucket, when the collision occurs, there is no way to accommodate the colliding value.
This results in the overlapping of values.
9. Traverse the given tree using Inorder, Preorder and Postorder traversals.
A B C D E F G H I J
Answer:
• Inorder : D H B E A F C I G J
• Preorder: A B D H E C F G I J
• Postorder: H D E B F I J G C A
10. There are 8, 15, 13, 14 nodes were there in 4 different trees. Which of them could have formed a full binary tree?
Answer: 15.
In general:
There are 2n-1 nodes in a full binary tree.
By the method of elimination:
Full binary trees contain odd number of nodes. So there cannot be full binary trees with 8 or 14 nodes, so rejected. With 13 nodes you can form a complete binary tree but not a full binary tree. So the correct answer is 15.
11. In the given binary tree, using array you can store the node 4 at which location?
Answer: At location 6
1 2 3 - - 4 - - 5
Root LC1 RC1 LC2 RC2 LC3 RC3 LC4 RC4
where LCn means Left Child of node n and RCn means Right Child of node n
12. For the given graph, draw the DFS and BFS?
Answer:
• BFS: A X G H P E M Y J
• DFS: A X H P E Y M J G
13. Classify the Hashing Functions based on the various methods by which the key value is found.
Answer: The list of Hashing functions is as follows:
• Direct method
• Subtraction method
• Modulo-Division method
• Digit-Extraction method
• Mid-Square method
• Folding method
• Pseudo-random method
14. What are the types of Collision Resolution Techniques and the methods used in each of the type?
Answer: The types of Collision Resolution Techniques are:
• Open addressing (closed hashing)
The methods used include:
• Overflow block
• Closed addressing (open hashing)
The methods used include:
• Linked list
• Binary tree
15. In RDBMS, what is the efficient data structure used in the internal storage representation?
Answer: 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.
16. What is a spanning Tree?
Answer: 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.
17. Does the minimum spanning tree of a graph give the shortest distance between any 2 specified nodes?
Answer: 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.
