Data Structures and Algorithms Flashcards

What is the time complexity of searching in a balanced binary search tree?

Answer: O(log n)

A balanced BST halves the search space at each step, resulting in logarithmic time complexity.

Which data structure operates on a Last-In-First-Out (LIFO) principle?

Answer: Stack

A stack follows LIFO ordering — the most recently added element is the first to be removed.

What is a hash collision?

Answer: When two different keys produce the same hash value

A hash collision occurs when different inputs map to the same index in a hash table, requiring collision resolution.

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

Answer: Efficient insertion and deletion without shifting elements

Linked lists allow O(1) insertion and deletion at known positions without moving other elements, unlike arrays.

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

Answer: Merge Sort with O(n log n)

Merge Sort consistently achieves O(n log n) time complexity using a divide-and-conquer approach.

What is the purpose of a queue data structure?

Answer: To process elements in First-In-First-Out (FIFO) order

Queues process elements in FIFO order, like a line at a store — first to arrive is first to be served.