Computer Science Algorithms & Data Structures

Question 1

What is the time complexity of binary search in a sorted array?

Accepted Answer

O(log n)

Answer

Binary search works by repeatedly dividing the search interval in half, eliminating a large portion of the data with each comparison. This logarithmic reduction in the search space results in a time complexity of O(log n), making it highly efficient for large sorted arrays.

Question 2

Which data structure is best suited for implementing a LIFO (Last In, First Out) order?

Accepted Answer

Stack

Answer

A stack is a linear data structure that follows the LIFO (Last In, First Out) principle, meaning the last element added is the first one to be removed. Operations like push (add) and pop (remove) occur at only one end, known as the top of the stack, perfectly aligning with LIFO behavior.

Question 3

What is the primary advantage of using a hash table?

Accepted Answer

Allows fast data retrieval in O(1) time

Answer

The primary advantage of using a hash table is its ability to provide average O(1) time complexity for data retrieval, insertion, and deletion operations. This constant time access is achieved by mapping keys directly to array indices using a hash function, making it incredibly fast for lookup-intensive tasks.

Question 4

Which sorting algorithm has the best average-case time complexity?

Accepted Answer

Merge Sort

Answer

Merge Sort has an average-case time complexity of O(n log n), which is generally considered the best among comparison-based sorting algorithms for large datasets. It achieves this efficiency by consistently dividing the array into halves, sorting them, and then merging them back together.

Question 5

What is the main advantage of using a linked list over an array?

Accepted Answer

Efficient insertions and deletions

Answer

A linked list offers efficient insertions and deletions compared to an array because elements do not need to be shifted when adding or removing nodes. Instead, only the pointers of adjacent nodes need to be updated, which can be done in O(1) time once the position is found.

(CS) Computer Science Practice Test

(CS) Computer Science Practice Test

Computer Science Algorithms & Data Structures