DS 2

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.    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

3.    What are the major data structures used in the following areas : RDBMS, Network data model & Hierarchical data model.
    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?
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?
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?
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?
    Polish and Reverse Polish notations.

8.    Convert the expression ((A + B) *  C – (D – E) ^ (F + G)) to equivalent Prefix and Postfix notations.
    Prefix Notation:
    ^ - * +ABC - DE + FG Postfix Notation:
    AB + C * DE - - FG + ^
9.    Sorting is not possible by using which of the following methods?
    (a) Insertion    
    (b) Selection    
    (c) Exchange     
    (d) Deletion

    (d) Deletion.
Using insertion we can perform insertion sort, using selection we can perform selection sort, using exchange we can perform the bubble sort (and other similar sorting methods). But no sorting method can be done just using deletion.

10.    What are the methods available in storing sequential files ?
    Straight merging,
    Natural merging,
    Polyphase sort,
    Distribution of Initial runs.

11.    How many different trees are possible with 10 nodes ?
    1014
    For example, consider a tree with 3 nodes(n=3), it will have the maximum combination of 5 different (ie, 2^3 - 3 =  5) trees.




13.    List out few of the Application of tree data-structure?
    The manipulation of Arithmetic expression,
    Symbol Table construction,
    Syntax analysis.

14.    List out few of the applications that make use of Multilinked Structures?
    Sparse matrix,
    Index generation.

15.    In tree construction which is the suitable efficient data structure?
    (a) Array           (b) Linked list              (c) Stack           (d) Queue   (e) none

(b) Linked list

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

17.    In an AVL tree, at what condition the balancing is to be done?
    If the ‘pivotal value’ (or the ‘Height factor’) is greater than 1 or less than –1.

18.    What is the bucket size, when the overlapping and collision occur at same time?
    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.

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



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…



26.    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.   

28.    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. 

29.    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.

30.    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.

32.    Which is the simplest file structure?
(a)    Sequential
(b)    Indexed
(c)    Random
(a) Sequential

33.    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.

DS 1

1.What data structes you will use if you want to go to first record from

the last and vice versa?

ans.: doubly linked circular list



2.  given a height balanced tree. If we add one more node , how

    many nodes gets unbalanced ? Ans. 3



3. Given a arbitrary pointer  to an element in a singly linked list?

    what is the time complexity for its deletion . Ans. O(n)



4. S->S+S; s->s*s; s->a

            how many parse trees possible : a+a*a+a   Ans. 5



5. order of  Hashing time



6) A choclate of size nXn is given and is to be made into pices of size 1x1. At a time both horizontal and a vertical cut is done. Find the order of complexity

a) 0(n2)

b) o(nlogn)

c) o(logn)

Ans : a



7) comparison between hashtable and binary tree?

8) No. of nodes of degree 2 in a binary tree with n leaf nodes.

    Ans. n-1



9. To sorting array of 10 elements which sorting is best

a)slection

b)bubble

c)tree sort

d)....

ans:a



10  To saving space point of view which sort is best

a)selection

b)insertion

c)both a & b

d)...



11Which statement is wrong on heap

a)Any two childs should not same

b)..

c)..

d)...

ans:a



12) cyclometric complexity..



13) how many  null pointer are there in N number binary tree

ans:N+1



14) Two sorted list of size n what are the maximum comparison in merge

ANs:2n-1

15) two sorted lists of n elements will take at least

fine the order of complexity?

a. 2n

b. n/2

c. square(n)



16)if there are n nodes in a binary tree, how many null pointers are there

ans:n+1;


17). if heap sort contains n elements, no of comparsions required are?

18) which of the following is efficient in terms of space

a. insertion sort

b. quick sort

c. selection

d. both a and c



19) in sorted table contains elements , which of the searching is

false

a. hash table

b. binary searching



20) in associated memory for fast accessing

which one is used

a. single linked list

b. double  "

c. hash table



21) for hashing which is best on terms of buckets

a)100 b)50 c)21 d)32  ans 32



22) max and avg. height of sorted binary tree

a. logn n

b n logn



23) implementation of priority queue

  a. tree

   b linked list

    c doubly linked list



24) For a binary tree with n nodes, How many nodes are there which

  has got both a parent and a child?


25) Bubble sort : Given sequence of numbers what will be order of sequences  after two iterations.
      Ans: very trivial, but you should know what bubble sort does.


26)Bubble sort : how many swap operations has been done in the above  process?


27)What data structures you should use for dictionary searching and it

        should be capable of doing spell check also ?

                Ans: Hashing


28)Which is the best scheduling algo. (given five of them)

        Ans.:  Shortest Job First with Pre-emption

29) Bubble  sort is given ., No of times it executes

 ans .  n(n-1)/2

30) The appriximate ratio for no of internal nodes to total no

31) precedence order from high to low (  ( )  ++  /  )

32) preorder of  A*(B+C)/D-G  (*+ABC/-DG)

33) B-tree (failure nodes at same level)

 of nodes in k-ary tree of depth  n.

 ans. 1/k


34) merge sort  time complexity (  O(n log n)   )

36)in binary search tree  which traversal is used for getting ascending

order values (inorder )



37) fun(n)

   {

    if(n<=2)

    return (1);

    else

     return ((fun(n-1)*fun(n-2));

     }

find the order of complexity of the programme.

possible answer ---- N(2^n)


38). average and worst time complexity in a sorted binary tree is?

39) a tree is given and ask to find its meaning (parse-tree)

    (expression tree)

    ans. ((a+b)-(c*d))  ( not confirmed)



40) Compute the complexity of Binary search.

Ans : O(lg n) ( Answer in detail. This is not a multiple choice question.

          It carries more marks.)



41) A search procedure which assosiates an address with a key value and

   provides a mechanism for dealing with two or more values assigned to the

   same address to the same address is called.

   a) linear earch

   b) binary search

 *   c) hash coded search

  d) radix search



42)which data struture is needed to convert infix notations to postfix

notations?

a. linear list

b. queue

c. tree

d. stack         
ans:d

43) recursive procedures are implemented by

a.queues

b.stacks

c.linked lists

d.strings

44) A linear list of elments in which deletion can be done from one end (front)and
insertion can take place only at the other end(rear)is known as

 *a) queues

  b)stacks

  c)trees

  d)deque



 45) A linear list in which elements can be added or removed at either end but not in the middle is known as
 a)queue
 *b)deque
 c)stack
 d)tree

46)which of the following sorting procedure is slowest
  a)quick sort
  b)heap sort
  c)shell sort
  *d)bubble sort
-> The point here is that you should have idea about these methods. If you are not master in these, It's fine, But you should know that there are some methods with these names.

48)  given a height balanced tree. If we add one more node , how many nodes gets unbalanced ?
Ans. 3

49) Given a arbitrary pointer  to an element in a singly linked list?what is the time complexity for its deletion . Ans. O(n)

50) S->S+S; s->s*s; s->a    how many parse trees possible : a+a*a+a 
Ans. 5

51) order of  Hashing time?

52) A chocolate of size nXn is given and is to be made into pices of size 1x1. At a time both horizontal and a vertical cut is done. Find the order of complexity

a) 0(n2)

b) o(nlogn)

c) o(logn)

Ans : a