DSA MIDTERM

Question 1

What is the characteristic behavior of a queue?
A. LIFO (Last In First Out)
B. FILO (First In Last Out)
C. FIFO (First In First Out)
D. Random Access

Answer 1

FIFO (First In First Out)

Question 2

Which of the following operations adds an item to the end of a queue?
A. dequeue
B. enqueue
C. pop
D. front

Answer 2

enqueue

Question 3

What does the dequeue() operation do in a queue?
A. Removes the item from the front
B. Adds an item to the rear
C. Checks if the queue is full
D. Returns the last item

Answer 3

Removes the item from the front

Question 4

Which operation checks if a queue is empty?
A. get-size()
B. is-empty()
C. front()
D. back()

Answer 4

is-empty()

Question 5

What is returned by the front() method in a queue?
A. The item at the front
B. The item at the back
C. The number of elements
D. A boolean value

Answer 5

The item at the front

Question 6

What is the main disadvantage of using a linked list over an array?
A. Requires more memory due to pointers
B. Slower access to elements
C. Only stores primitive types
D. Can’t grow in size

Answer 6

Requires more memory due to pointers

Question 7

Which type of linked list can only be traversed in one direction?
A. Singly Linked List
B. Doubly Linked List
C. Circular Linked List
D. Binary Tree

Answer 7

Singly Linked List

Question 8

In a doubly linked list, each node contains:
A. One data field and one link
B. One data field and two links
C. Only links
D. One link and one method

Answer 8

One data field and two links

Question 9

In a circular linked list, the last node points to:
A. NULL
B. Middle node
C. First node
D. Random node

Answer 9

First node

Question 10

Which of the following is not a queue operation?
A. enqueue()
B. traverse()
C. dequeue()
D. front()

Answer 10

traverse()

Question 11

What happens when a queue is full?
A. No more items can be enqueued
B. It resets
C. It removes the front item
D. It duplicates the rear item

Answer 11

No more items can be enqueued

Question 12

Which method removes the front element without returning it?
A. pop()
B. dequeue()
C. front()
D. push()

Answer 12

pop()

Question 13

What is the time complexity of insertion at the rear of a queue using a circular array?
A. O(1)
B. O(n)
C. O(log n)
D. O(n log n)

Answer 13

O(1)

Question 14

What does the get-size() method return?
A. The last index
B. The number of elements in the queue
C. The queue capacity
D. Boolean value

Answer 14

The number of elements in the queue

Question 15

What is the pointer to the first node in a linked list called?
A. HEAD
B. TAIL
C. START
D. NODE

Answer 15

HEAD

Question 16

In a singly linked list, the last node points to:
A. First node
B. NULL
C. Head node
D. Itself

Answer 16

NULL

Question 17

What type of linked list allows bidirectional traversal?
A. Singly linked list
B. Doubly linked list
C. Queue
D. Stack

Answer 17

Doubly linked list

Question 18

Which type of linked list does not end in NULL?
A. Singly Linked List
B. Doubly Linked List
C. Circular Linked List
D. Static List

Answer 18

Circular Linked List

Question 19

What is the main purpose of using a circular array in a queue?
A. Simplifies logic
B. Saves memory
C. Speeds up sorting
D. Avoids overflow

Answer 19

Saves memory

Question 20

Which queue operation is equivalent to inserting at the end of the list?
A. enqueue
B. dequeue
C. front
D. pop

Answer 20

enqueue

Question 21

A queue always allows insertions at the front.
T/F

Answer 21

False

Question 22

A singly linked list node stores both data and a pointer to the next node.

Answer 22

True

Question 23

Doubly linked lists require three references per node.

Answer 23

False

Question 24

In a circular linked list, traversal can go infinitely if not properly terminated.

Answer 24

True

Question 25

A linked list uses contiguous memory blocks to store its elements.

Answer 25

False

Question 26

What type of algorithm is Merge Sort? A. Greedy B. Divide and conquer C. Backtracking D. Dynamic programming

Answer 26

Divide and conquer

Question 27

Which of the following best describes the process of Merge Sort? A. Sorts by comparing each element to all others B. Uses pivot to partition arrays C. Divides the array and merges sorted sub-arrays D. Repeatedly places maximum elements at the end

Answer 27

Divides the array and merges sorted sub-arrays

Question 28

What is the time complexity of Merge Sort in the best, average, and worst cases? A. O(n²) B. O(n) C. O(n log n) D. O(log n)

Answer 28

O(n log n)

Question 29

What does the merge() function in Merge Sort do? A. Deletes elements B. Finds the median C. Merges two sorted sub-arrays D. Finds the pivot

Answer 29

Merges two sorted sub-arrays

Question 30

In Merge Sort, the base case of recursion is when the array has: A. Two elements B. One element C. Three elements D. No elements

Answer 30

One element

Question 31

Quick Sort is a type of: A. Graph algorithm B. Greedy algorithm C. Divide and conquer algorithm D. Dynamic programming algorithm

Answer 31

Divide and conquer algorithm

Question 32

In Quick Sort, which of the following is true about the pivot? A. It is always the largest element B. It is always the middle element C. It is the element used to partition the array D. It is the smallest element in the array

Answer 32

It is the element used to partition the array

Question 33

What is the worst-case time complexity of Quick Sort? A. O(n log n) B. O(n) C. O(n²) D. O(log n)

Answer 33

O(n²)

Question 34

What condition causes the worst case in Quick Sort? A. Array is partially sorted B. Array has duplicates C. Array is already sorted D. Array has only one element

Answer 34

Array is already sorted

Question 35

What does the partition() function in Quick Sort do? A. Swaps all elements B. Sorts a sub-array C. Divides the array based on pivot D. Merges sub-arrays

Answer 35

Divides the array based on pivot

Question 36

Which of the following is assumed by Bucket Sort for optimal performance? A. All elements are integers B. Elements are normally distributed C. Elements are uniformly distributed in [0, 1) D. Elements are in ascending order

Answer 36

Elements are uniformly distributed in [0, 1)

Question 37

Bucket Sort performs best when: A. All elements are duplicates B. Elements are randomly distributed C. Array is sorted D. Array has large negative numbers

Answer 37

Elements are randomly distributed

Question 38

What sorting algorithm is commonly used inside each bucket in Bucket Sort? A. Merge Sort B. Quick Sort C. Insertion Sort D. Selection Sort

Answer 38

Insertion Sort

Question 39

Which data structure is typically used for storing buckets? A. Arrays B. Stacks C. Linked Lists D. Trees

Answer 39

Linked Lists

Question 40

Which of the following best describes Bucket Sort’s time complexity on average? A. O(n²) B. O(log n) C. O(n) D. O(n log n)

Answer 40

O(n)

Question 41

Radix Sort sorts elements based on: A. Their values only B. Their digits C. Their length D. Their frequency

Answer 41

Their digits

Question 42

In Radix Sort, sorting is done from: A. Most significant digit to least B. Least significant digit to most C. Left to right D. In reverse order

Answer 42

Least significant digit to most

Question 43

Radix Sort uses which type of sorting technique internally? A. Merge Sort B. Insertion Sort C. Counting Sort D. Selection Sort

Answer 43

Counting Sort

Question 44

Which of the following sorting algorithms is non-comparative? A. Merge Sort B. Quick Sort C. Radix Sort D. Bubble Sort

Answer 44

Radix Sort