DATA STRUCTURES MCQ
1. Which of the following data structures allows rapid search, insertion, and
deletion operations?
a) Array
b) Linked List
c) Hash Table
d) Binary Tree
2. Which data structure follows the Last In First Out (LIFO) principle?
a) Queue
b) Stack
c) Tree
d) Linked List
3. What is the minimum number of queues required to implement a priority
queue?
a) One
b) Two
c) Three
d) Four
4. Which data structure is used in the implementation of a breadth-first
search algorithm?
a) Stack
b) Queue
c) Heap
d) Linked List
5. Which of the following data structures uses dynamic memory allocation?
(a) Array
(b) Linked List
(c) Stack
(d) Queue
DATA STRUCTURES MCQ
6. A doubly linked list allows efficient:
(a) Insertion at the beginning only
(b) Insertion and deletion at any position
(c) Search from the beginning
(d) Random access
7. What is the space complexity of a singly linked list representation of a
stack?
(a) O(1)
(b) O(n)
(c) O(log n)
(d) O(n^2)
8. The Floyd-Warshall algorithm is used for:
(a) Finding shortest paths between all pairs of vertices in a directed
graph
(b) Finding Eulerian circuits in a graph
(c) Detecting cycles in a graph
(d) Topological sorting of a directed acyclic graph
9. What is the best-case time complexity of binary search for an element in
a sorted array?
(a) O(1)
(b) O(log n)
(c) O(n)
(d) O(n^2)
10. What is the worst-case time complexity of binary search for an element
in a sorted array?
(a) O(1)
(b) O(log n)
(c) O(n)
(d) O(n^2)
DATA STRUCTURES MCQ
11)Which data structure is typically used to implement a First In First Out
(FIFO) queue?
(a) Array
(b) Linked List
(c) Stack
(d) Hash Table
Answer: (b) Linked List
12) In a binary search tree, which traversal method visits the nodes in
ascending order?
(a) Preorder
(b) Inorder
(c) Postorder
(d) Level order
Answer: (b) Inorder
13) Which data structure is commonly used to implement a heap?
(a) Array
(b) Linked List
(c) Hash Table
(d) Binary Tree
Answer: (a) Array
14) Which of the following is not a type of tree traversal?
(a) Depth-first
(b) Breadth-first
(c) Height-first
(d) Level-order
Answer: (c) Height-first
DATA STRUCTURES MCQ
15) What is the time complexity of finding the maximum element in a binary
search tree?
(a) O(n)
(b) O(log n)
(c) O(n^2)
(d) O(1)
Answer: (a) O(n)
16) Which data structure is used for topological sorting of a directed acyclic
graph (DAG)?
(a) Queue
(b) Stack
(c) Heap
(d) Linked List
Answer: (b) Stack
17) Which data structure is suitable for implementing a cache with Least
Recently Used (LRU) eviction policy?
(a) Array
(b) Linked List
(c) Queue
(d) Stack
Answer: (b) Linked List
18) What is the worst-case time complexity for searching an element in a
hash table with chaining collision resolution?
(a) O(1)
(b) O(log n)
(c) O(n)
(d) O(n^2)
DATA STRUCTURES MCQ
Answer: (c) O(n)
19) Which data structure is used in the implementation of Dijkstra's shortest
path algorithm?
(a) Queue
(b) Stack
(c) Heap
(d) Linked List
20) Which data structure is typically used for implementing a symbol table
in compilers?
(a) Hash Table
(b) Binary Search Tree
(c) Linked List
21. Which data structure is commonly used for implementing undo
functionality in text editors?
(A) Stack
(B) Queue
(C) Linked List
(D) Binary Tree
22. What is the time complexity of inserting an element at the end of a
singly linked list with tail pointer?
(A) O(1)
(B) O(log n)
(C) O(n)
(D) O(n^2)
DATA STRUCTURES MCQ
23. Which data structure is used for implementing the "undo" operation in a
graphics drawing program?
(A) Queue
(B) Stack
(C) Linked List
(D) Binary Tree
24. In a binary tree, the maximum number of nodes at level "k" is:
(A) 2^(k-1)
(B) 2^k
(C) k^2
(D) 2^(k+1) - 1
25. Which data structure is typically used for implementing a Least
Recently Used (LRU) cache?
(A) Array
(B) Linked List
(C) Queue
(D) Stack
26. In which traversal of a binary tree are the nodes processed in the order:
left, root, right?
(A) Preorder
(B) Inorder
(C) Postorder
(D) Level order
27. Which data structure is used for implementing the Open Addressing
strategy in hashing?
(A) Array
DATA STRUCTURES MCQ
(B) Linked List
(C) Queue
(D) Stack
28. What is the time complexity of inserting an element into a binary search
tree?
(A) O(1)
(B) O(log n)
(C) O(n)
(D) O(n^2)
29. Which data structure is used in the implementation of the Kruskal's
minimum spanning tree algorithm?
(A) Queue
(B) Stack
(C) Heap
(D) Linked List
30. Which data structure is used for efficient implementation of Prim's
algorithm for minimum spanning tree?
(A) Queue
(B) Stack
(C) Heap
(D) Linked List
31. The minimum number of fields in each node of a doubly linked list is
____
(A) 2
(B) 3
(C) 4
DATA STRUCTURES MCQ
(D) None of the above
32. A graph in which all vertices have equal degree is known as ____
(A) Complete graph
(B) Regular graph
(C) Multigraph
(D) Simple graph
33. A vertex of in-degree zero in a directed graph is called a/an
(A) Root vertex
(B) Isolated vertex
(C) Sink
(D) Articulation point
34. A graph is a tree if and only if the graph is
(A) Directed graph
(B) Contains no cycles
(C) Planar
(D) Completely connected
35. The elements of a linked list are stored
(A) In a structure
(B) In an array
(C) Anywhere the computer has space for them
(D) In contiguous memory locations
36. A parentheses checker program would be best implemented using
(A) List
(B) Queue
(C) Stack
(D) Any of the above
DATA STRUCTURES MCQ
37. To perform level-order traversal on a binary tree, which of the
the following data structure will be required?
(A) Hash table
(B) Queue
(C) Binary search tree
(D) Stack
38. Which of the following data structures is required to convert
arithmetic expression in infix to its equivalent postfix notation?
(A) Queue
(B) Linked list
(C) Binary search tree
(D) None of the above
39. A binary tree in which all its levels except the last, have maximum
numbers of nodes and all the nodes in the last level have only one
child it will be its left child. Name the tree.
(A) Threaded tree
(B) Complete binary tree
(C) M-way search tree
(D) Full binary tree
40. Which of the following data structures is more appropriate for
implementing quick sort iteratively?
(A) Deque
(B) Queue
(C) Stack
(D) Priority queue