CCS Data Structures and Algorithms 2

Question 1

Which data structure follows the LIFO (Last In, First Out) principle?

Accepted Answer

Stack

Answer

A stack operates on LIFO, where the last element added is the first one removed.

Question 2

What is the time complexity of accessing an element in an array by index?

Accepted Answer

O(1)

Answer

Array index access is O(1) because elements are stored at contiguous memory locations.

Question 3

In a binary search tree (BST), which traversal produces nodes in sorted ascending order?

Accepted Answer

In-order

Answer

In-order traversal (left, root, right) visits BST nodes in ascending sorted order.

Question 4

What is the worst-case time complexity of quicksort?

Accepted Answer

O(n²)

Answer

Quicksort degrades to O(n²) when the pivot is consistently the smallest or largest element.

Question 5

Which data structure is best suited for implementing a breadth-first search (BFS)?

Accepted Answer

Queue

Answer

BFS uses a queue to process nodes level by level in FIFO order.

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