Computer Knowledge

Data Structures and Algorithms

1,518 Questions

Data Structures and Algorithms form the core of computer science, focusing on arrays, linked lists, trees, and sorting mechanisms. These concepts are essential for solving complex computational problems efficiently. Test takers preparing for technical and administrative IT exams will find these questions highly relevant.

Array OperationsLinked List ApplicationsSorting AlgorithmsTree Data StructuresMultilevel IndexingAlgorithm Time Complexity

Data Structures and Algorithms Questions

Multiple choice

When a multi-dimensional array is accessed, each array index is

  1. separated by commas

  2. surrounded by brackets and separated by commas

  3. surrounded by brackets

  4. separated by commas and surrounded by brackets
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

In multi-dimensional arrays, each dimension's index is enclosed in its own set of square brackets (e.g., array[i][j]).

Multiple choice

In a linked list

  1. each link contains a pointer to the next link

  2. an array of pointers points to the link

  3. no link contains data

  4. the links are stored in an array
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

A linked list is a linear data structure where elements are not stored in contiguous memory locations. Each element (node) contains data and a pointer (or reference) to the next node in the sequence.

Multiple choice

Which of the following places the common data elements in order from smallest to largest?

  1. Character, file, record, field, database

  2. Character, record, field, database, file

  3. Character, field, record, file, database

  4. Bit, byte, character, record, field, file, database,

  5. None of these
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The standard hierarchy of data organization from smallest to largest is: Character (or bit/byte), Field, Record, File, and Database. This represents the logical structure of data storage.

Multiple choice

Which structure is more amenable for searching?

  1. Binary tree

  2. Singular linked list

  3. Double linked list

  4. Array
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Binary trees, specifically balanced ones, allow for O(log n) search time, which is significantly faster than the O(n) linear search required for linked lists or unsorted arrays.

Multiple choice

Find the odd one out.

  1. Ascending priority queue - Min Heap

  2. Descending priority queue - Max Heap

  3. Binary Search Tree - Sorting

  4. B-Tree - Index Sequential Search
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The other options pair a data structure with its primary application or property (Priority Queues with Heaps, B-Trees with indexing). A Binary Search Tree is a data structure, not a sorting algorithm itself, though it can be used for sorting.

Multiple choice

Consider the following program fragment for reversing the digits in a given integer to obtain a new integer. Let n = d1d2... dm. int n, rev; rev = 0; while (n > 0) { rev = rev * 10 + n % 10; n = n/10; } The loop invariant condition at the end of the ith iteration is

  1. n = d1d2... dm-i....and rev = dmdm-1..dm-i+1

  2. n = dm-i+1...dm-1dm (or) rev = dm-i...d2d1

  3. n ¹ rev

  4. n = d1d2...dm (or) rev = dm...d2d1
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The loop reverses the integer. After i iterations, the last i digits of n have been moved to the front of rev in reverse order. Thus, n contains the remaining digits and rev contains the reversed prefix.