Most frequently asked data structure interview question.

                                            

                                             PART-2                                                  

 21.  In the given binary tree, using array you can store the node 4 at which location?

 

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

22. Sort the given values using Quick Sort?

           

65

70

75

80

85

60

55

50

45

            Sorting takes place from the pivot value, which is the first value of the given elements, this is marked bold. The values at the left pointer and right pointer are indicated using ^L and ^R respectively.    

65

70L

75

80

85

60

55

50

45R

Since pivot is not yet changed the same process is continued after interchanging the values at ^L and ^R positions

65

45

75 L

80

85

60

55

50 R

70

                       

65

45

50

80 L

85

60

55 R

75

70

65

45

50

55

85 L

60 R

80

75

70

65

45

50

55

60 R

85 L

80

75

70

                       

When the L and R pointers cross each other the pivot value is interchanged with the value at right pointer. If the pivot is changed it means that the pivot has occupied its original position in the sorted order (shown in bold italics) and hence two different arrays are formed, one from start of the original array to the pivot position-1 and the other from pivot position+1 to end.

60 L

45

50

55 R

65

85 L

80

75

70 R

55 L

45

50 R

60

65

70 R

80 L

75

85

50 L

45 R

55

60

65

70

80 L

75 R

85

In the next pass we get the sorted form of the array.

45

50

55

60

65

70

75

80

85

23. For the given graph, draw the DFS and BFS?

           

 

BFS:     A X G H P E M Y J

DFS:    A X H P E Y M J G

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

Direct method,

·         Subtraction method,

·         Modulo-Division method,

·         Digit-Extraction method,

·         Mid-Square method,

·         Folding method,

·         Pseudo-random method.         

25. 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…

25. 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.   

26. Draw the B-tree of order 3 created by inserting the following data arriving in sequence – 92  24  6  7  11  8  22  4  5  16  19  20  78

 

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

·         Incomplete Binary Tree

·         Complete Binary Tree     

·         Full Binary Tree

ANSWER:

            (b) Complete Binary Tree.

Explanation:

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. 

28. 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.

29. 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.

30. Convert the given graph with weighted edges to minimal spanning tree.

           

 

           

the equivalent minimal spanning tree is:

31. Which is the simplest file structure?

·         Sequential

·         Indexed

·         Random

ANSWER:

 Sequential

32. 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.

33. Draw a binary Tree for the expression:

            A * B - (C + D) * (P / Q)

 

34. For the following COBOL code, draw the Binary tree?

01 STUDENT_REC.

     02 NAME.

          03 FIRST_NAME PIC X(10).

                03 LAST_NAME PIC X(10).

           

            02 YEAR_OF_STUDY.

                03 FIRST_SEM PIC XX.

                03 SECOND_SEM PIC XX.