## **Data Structures MCQ's Questions Set 1**

**Q.1.** What is the worst case run-time complexity of binary search algorithm?

- Ο(n2)
- Ο(nlog n)
- Ο(n3)
- Ο(n)

**Answer:- (4)**

**Q.2. **If there's no base criteria in a recursive program, the program will

- not be executed.
- execute until all conditions match.
- execute infinitely.
- obtain progressive approach.

**Answer:- (3)**

**Q.3. **The depth of complete binary tree is given by

- Dn = n log2n
- Dn = n log2n +1
- Dn = log2n
- Dn = log2n + 1

**Answer:- (4)**

**Q.4. **The postfix form of the expression (A+ B)*(C*D- E)*F / G is?

- AB+ CD*E – FG /**
- AB + CD* E – F **G /
- AB + CD* E – *F *G /
- AB + CDE * – * F *G /

**Answer:- (3)**

**Q.5.** Which data structure is needed to convert infix notation to postfix notation?

- Branch
- Tree
- Queue
- Stack

**Answer:- (4)**

**Q.6. **One can convert a binary tree to its mirror image by traversing it in

- Inorder
- Preorder
- Postorder
- None of the above

**Answer:- (3)**

**Q.7. **For an undirected graph with n vertices and e edges, the sum of degree of each vertex is equal to

- 2n
- 2e
- (e2+1)/2
- (2n-1)/2

**Answer:- (2)**

**Q.8. ** A data structure in which elements can be inserted or deleted at/from both the ends but not in the middle is?

- Queue
- Circular queue
- Dequeue
- Priority queue

**Answer:- (3)**

**Q.9. **What would be the asymptotic time complexity to add a node at the end of singly linked list, if the pointer is initially pointing to the head of the list?

- O(1)
- O(n)
- θ(n)
- θ(1)

**Answer:- (3)**

**Q.10. **Consider the following definition in c programming language

struct node { int data; struct node * next; } typedef struct node NODE; NODE *ptr; |
---|

Which of the following c code is used to create new node?

- ptr = (NODE*)malloc(sizeof(NODE));
- ptr = (NODE*)malloc(NODE);
- ptr = (NODE*)malloc(sizeof(NODE*));
- ptr = (NODE)malloc(sizeof(NODE));

**Answer:- (1)**

**Q.11. **Which of the following points is/are not true about Linked List data structure when it is compared with array?

- Arrays have better cache locality that can make them better in terms of performance
- It is easy to insert and delete elements in Linked List
- Random access is not allowed in a typical implementation of Linked Lists
- Access of elements in linked list takes less time than compared to arrays

**Answer:- (4)**

**Q.12. **You are given pointers to first and last nodes of a singly linked list, which of the following operations are dependent on the length of the linked list?

- Delete the first element
- Insert a new element as a first element
- Delete the last element of the list
- Add a new element at the end of the list

**Answer:- (3)**

**Q.13. **What is a memory efficient double linked list?

- Each node has only one pointer to traverse the list back and forth
- The list has breakpoints for faster traversal
- An auxiliary singly linked list acts as a helper list to traverse through the doubly linked list
- A doubly linked list that uses bitwise AND operator for storing addresses

**Answer:- (1)**

**Q.14. **How do you calculate the pointer difference in a memory efficient double linked list?

- head xor tail
- pointer to previous node xor pointer to next node
- pointer to previous node – pointer to next node
- pointer to next node – pointer to previous node

**Answer:- (2)**

**Q.15. **Which of the following application makes use of a circular linked list?

- Undo operation in a text editor
- Recursive function calls
- Allocating CPU to resources
- Implement Hash Tables

**Answer:- (3)**

**Q.16. **Array implementation of Stack is not dynamic, which of the following statements supports this argument?

- space allocation for array is fixed and cannot be changed during run-time
- user unable to give the input for stack operations
- a runtime exception halts execution
- improper program compilation

**Answer:- (1)**

**Q.17. **Which of the following data structures can be used for parentheses matching?

- n-ary tree
- queue
- priority queue
- stack

**Answer:- (4)**

**Q.18. **What is the time complexity of enqueue operation?

- O(logn)
- O(nlogn)
- O(n)
- O(1)

**Answer:- (4)**

**Q.19. **In case of insertion into a linked queue, a node borrowed from the __________ list is inserted in the queue.

- AVAIL
- FRONT
- REAR
- NULL

**Answer:- (1)**

**Q.20. **Which of the following is true about linked list implementation of queue?

- In push operation, if new nodes are inserted at the beginning of linked list, then in pop operation, nodes must be removed from end
- In push operation, if new nodes are inserted at the beginning, then in pop operation, nodes must be removed from the beginning
- In push operation, if new nodes are inserted at the end, then in pop operation, nodes must be removed from end
- In push operation, if new nodes are inserted at the end, then in pop operation, nodes must be removed from beginning.

**Answer:- (1)**

**Data Structures Interview Questions Set 1 Click here**

**Data Structures & Algorithms(DSA) MCQ's Questions Set 1**

**Data Structures and Algorithm (DSA) Queue MCQ'S Question Set 2**

** Technical-MCQs For Placement Preparation**