DATA STRUCTURE

1- What data structure can be used to check if a syntax hasbalanced paranthesis ?

A - queue

B - tree

C - list

D - stack

Answer : DExplanationStack uses LIFO method which is good for checking matchingparanthesis.

2. What does the following function do for a given Linked Listwith first node as head?

void fun1(struct node* head){ if(head == NULL) return;

fun1(head->next); printf("%d ", head->data);}

A Prints all nodes of linked lists

B Prints all nodes of linked list in reverse order

C Prints alternate nodes of Linked List

D Prints alternate nodes in reverse order

B

3 - Which of the following asymptotic notation is the worstamong all?

A - Ο(n+9378)

B - Ο(n3)

C - nΟ(1)

D - 2Ο(n)

D

4 - Which of the following searching techniques do not requirethe data to be in sorted form

A - Binary Search

B – Linear search

C-Both A and B

D-None of the above

Answer : AExplanationBoth binary requires data set to be in sorted form. Linear searchcan work even if the data is not sorted.

5 - Which method can find if two vertices x & y have pathbetween them?

A - Depth First Search

B - Breadth First Search

C - Both A & B

D - None A or B

Answer : CExplanationBy using both BFS and DFS, a path between two vertices of aconnected graph can be determined.

6 - Tower of hanoi is a classic example of

A - divide and conquer

B - recursive approach

C - B but not A

D - Both A & B

Answer : DExplanationThe recursive approach of tower of hanoi uses divide andconquer method.

7.Which of the following is true about linked listimplementation of stack?a. In push operation, if new nodes are inserted at thebeginning of linked list, then in pop operation, nodes mustbe removed from end.b. In push operation, if new nodes are inserted at the end, then inpop operation, nodes must be removed from the beginning.c. Both of the aboved. None of the above

D

8.The result evaluating the postfix expression 10 5 + 60 6 / * 8– isA 284

B 213

C 142

D 71

C

9.Which of the following can be solved by dynamicprogramming approach?

A – All pair shortest path problem

B – 0/1 Knapsack problem

C- None of the above

D - All of the above

Answer : DExplanationAll mentioned use dynamic programming approach. Beforesolving the in-hand sub-problem, dynamic algorithm will try toexamine the results of previously solved sub-problems. Thesolutions of sub-problems are combined in order to achieve thebest solution.

10 - Recursion uses more memory space than iteration because

A - it uses stack instead of queue.

B - every recursive call has to be stored.

C - both A & B are true.

D - None of the above are true.

Answer : BExplanationRecursion uses stack but the main reason is, every recursivecall needs to be stored separately in the memory.

Q 11 - What is the worst case run-time complexity of quicksortsort algorithm?

A - Ο(n2)

B - Ο(nlog n)

C - Ο(n3)

D - Ο(n)

Answer : AExplanation3 cases

1)All numbers are equal

2)Numbers are in decreasing order

3) Numbers are in increasing order

12.

How many stacks are needed to implement a queue.

How many queues are needed to implement a stack.

a)1 , 1

b)2 ,1

c)1,2

d)2,2

D

13.Which algorithm is used to construct minimum spanningtree?

A.Prims and krushkal algo

B.Prims and dijkstras algo

C.Krushkal and dijkstras

D.Prims and krushkal and dijkstras algo

A

14.How many distinct binary search trees can be created outof 4 distinct keys?

A 4

B 14

C 24

D 42

14Catalan no:(2n)!/(n!*(n+1)!)

15.Which of the following traversal outputs the data in sortedorder in a BST?

A Preorder

B Inorder

C Postorder

D Level order

B

16.What are the worst-case complexities of insertion and deletionof a key in a binary search tree?A Θ(logn) for both insertion and deletion

B Θ(n) for both insertion and deletion

C Θ(n) for insertion and Θ(logn) for deletion

D Θ(logn) for insertion and Θ(n) for deletion

B

17.A max-heap is a heap where the value of each parent isgreater than or equal to the values of its children. Which of thefollowing is a max-heap?

A A

B B

C C

D D

B

18.Consider a binary max-heap implemented using an array. Whichone of the following array represents a binary max-heap? A 25,12,16,13,10,8,14

B 25,12,16,13,10,8,14

C 25,14,16,13,10,8,12

D 25,14,12,13,10,8,16

C

19.What is the content of the array after two delete operationson the correct answer to the previous question(deleting root node)?A 14,13,12,10,8

B 14,12,13,8,10

C 14,13,8,12,10

D 14,13,12,8,10

D

20.The keys 12, 18, 13, 2, 3, 23, 5 and 15 are inserted into aninitially empty hash table of length 10 using open addressing(CLOSED HASHING)with hash function h(k) = k mod 10 andlinear probing. What is the resultant hash

table?A A

B B

C C

D D

C

open addressing =CLOSED HASHING

closed addressing=OPEN HASHING

Open addressing, or closed hashing, is a method of collisionresolution in hash tables. With this method a hash collision isresolved by probing, or searching through alternate locations inthe array (the probe sequence) until either the target record isfound, or an unused array slot is found, which indicates thatthere is no such key in the table.

Well known probe sequences include: linear probing in whichthe interval between probes is fixed--often at 1. quadraticprobing in which the interval between probes increases linearly(hence, the indices are described by a quadraticfunction). double hashing in which the interval between probesis fixed for each record but is computed by another hashfunction.

21.Which of the following statement(s) is TRUE?I. A hash function takes a message of arbitrary length and

generates a fixed length code.II.A hash function takes a message of fixed length and

generates a code of variable length.

III.A hash function may give the same hash value for distinctmessages.

A.I onlyB.II and III onlyC.I and III onlyD.II only

C

22.The Breadth First Search algorithm has been implemented usingthe queue data structure. One possible order of visiting thenodes of the following graph

isA MNOPQR

B NQMPOR

C QMNPRO

D QMNPOR

C

23.Consider the DAG with Consider V = {1, 2, 3, 4, 5, 6},shown below. Which of the following is NOT a topological

ordering? A 1 2 3 4 5 6

B 1 3 2 4 5 6

C 1 3 2 4 6 5

D 3 2 4 1 6 5

D

24.Worst case complexity and average case complexity ofHeight of binary search tree is (complexity is in Big O)

a)log n , n

b)n, log n

c)n,n

d)log n,log n

C

25.The height of a binary tree is the maximum number of edgesin any root to leaf path. The maximum number of nodes andminimum number of nodes in a binary tree of height h is:

a)2^(h+1) 2^(h)-1

b) 2^(h+1)-1 2^(h-1)-1

c) 2^(h+1)-1 2^(h)

d) 2^(h) 2^(h+1)-1

C

26. In the worst case, the number of comparisons needed tosearch a singly linked list of length n for a given element is

a)log2n

c)n

d) log2n – 1

d)n/2

B

27. You are given pointers to first and last nodes of a singlylinked list, which of the following operations are dependent onthe length of the linked list?

a) Delete the first element

b) Insert a new element as a first element

c) Delete the last element of the list

d) Add a new element at the end of the list

C

28.Considerthefollowingfunction totraverse alinkedlist.

voidtraverse(structNode*head){ while(head-->next !=NULL) { printf("%d ",head->data); head =head->next; }}

Which ofthefollowingis FALSE aboutabovefunction?

a.Th

e

funct

ion

may

crash

when

the

linke

d list

is

empt

y

b.Th

e

funct

ion

does

n't

print

the

last

node

when

the

linke

d list

is not

empt

y

c.Th

e

funct

ion is

impl

emen

ted

incor

rectl

y

beca

use it

chan

ges

head

C

29. Predict the output of following program

#include <stdio.h>int f(int n){ if(n <= 1) return 1;

if(n%2 == 0) return f(n/2); return f(n/2) + f(n/2+1);}

int main(){ printf("%d", f(11)); return 0;}A)3

B)4

C)5

D)STACK OVERFLOW

C

30. Here is an infix notation ((A+B)*C-(D-E))^(F+G). Choose the correct postfix notation of the above from the givenoptions. a. AB+CD*E--FG+^ b. AB+C*DE--FG+^ c. AB+C*DE-FG-+^ d. A+BC*DE-FG-+^

B

31. What is the best time complexity of bubble sort?

a)n2

b)logn

c)n

d)nlogn

C

int main()

{ int arr[] = {10, 20, 30, 400, 50}, i, j, isSwapped;

int n = sizeof(arr) / sizeof(*arr),t;

isSwapped = 1;

for(i = 0; i < n - 1 && isSwapped; ++i)

{ isSwapped = 0;

for(j = 0; j < n - i - 1; ++j)

{

if (arr[j] > arr[j + 1])

{ t=arr[j];

arr[j]=arr[j+1];

arr[j+1]=t;

}

isSwapped = 1;

}

}

for(i = 0; i < n; ++i)

printf("%d ", arr[i]);

return 0; }

32. The auxiliary space of insertion sort is O(1), what does O(1)mean ?

a.The memory (space) required to process the data is notconstant.

b.It means the amount of extra memory Insertion Sort consumesdoesn't depend on the input. The algorithm should use the sameamount of memory for all inputs.

c.It takes only 1 kb of memory .

c.It is the speed at which the elements are traversed

B