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

The following numbers are inserted into an empty binary search tree in the given order: 10, 1, 3, 5, 15, 12, 16. What is the height of the binary search tree (the height is the maximum distance of a leaf node from the root)?

  1. 2

  2. 3

  3. 4

  4. 6
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Inserting 10, 1, 3, 5, 15, 12, 16 into a BST creates a tree where 10 is the root, 1 is the left child, 3 is the right child of 1, 5 is the right child of 3, 15 is the right child of 10, 12 is the left child of 15, and 16 is the right child of 15. The longest path from the root (10) to a leaf (5 or 16) has 3 edges (10-1-3-5).

Multiple choice

Postorder traversal of a binary search tree T produces the following sequence of keys:

10, 9, 23, 22, 27, 25, 15, 50, 95, 60, 40, 29

Which of the following sequences of keys can be the result of an inorder traversal of the tree T?

  1. 9, 10, 15, 22, 23, 25, 27, 29, 40, 50, 60, 95

  2. 9, 10, 15, 22, 40, 50, 60, 95, 23, 25, 27, 29

  3. 29, 15, 9, 10, 25, 22, 23, 27, 40, 60, 50, 95

  4. 95, 50, 60, 40, 27, 23, 22, 25, 10, 9, 15, 29

Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Option (1) is correct.

Multiple choice

Consider the following C program segment struct CellNode { struct CellNode *leftChild ; int element; struct CellNode *rightChild ; }; int DoSomething (struct CellNode *ptr) { int value = 0 ; if (ptr ! = NULL) { if (ptr->leftChild ! = NULL) value = 1 + DoSomething (ptr - > leftChild); if (ptr - > rightChild ! = NULL) value = max (value, 1 + DoSomething (ptr - > rightChild)) ; } return (value); } The value returned by the function do something when a pointer to the root of a non-empty tree is passed as argument is

  1. the number of leaf nodes in the tree

  2. the number of nodes in the tree

  3. the number of internal nodes in the tree

  4. the height of the tree
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The function recursively calculates the maximum depth of the tree. For each node, it returns 1 plus the maximum of the heights of its left and right subtrees, which is the definition of tree height.

Multiple choice

How can we increase the efficiency of the doubly linked list ?

  1. By accessing the last element of the list.

  2. By accessing any element from the list.

  3. By traversing the list in left or right direction from node.

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

When a linked list is connected doubly, i.e doubly linked list in which each node contains the address of next as well as previous node is very efficient other than we transverse the list from any direction of side of any node. 

Multiple choice

TM is more powerful than FSM because

  1. tape movement is confined to one direction

  2. it has no finite state control

  3. it has the capability to remember arbitrary long sequences of input symbols

  4. none of these
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

A Turing Machine (TM) has an infinite tape that allows it to read, write, and move in both directions, providing it with memory that is not limited by the number of states. FSMs have a fixed, finite amount of memory determined by their state count.

Multiple choice

Consider a hashing function that resolves collision by quadratic probing. Assume the address space to be indexed from 1 to 8. If a collision occurs at position 4, which of the following locations will never be probed?

  1. 4

  2. 5

  3. 8

  4. 2
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Quadratic probing uses the sequence (h(k) + i^2) mod m. Starting at 4 with m=8, the sequence is 4, (4+1) mod 8 = 5, (4+4) mod 8 = 0 (or 8 if 1-indexed), (4+9) mod 8 = 5, (4+16) mod 8 = 4. Since the probe sequence repeats, locations like 2, 3, 6, and 7 are never reached.

Multiple choice

The stacks cannot be used to

  1. evaluate an arithmetic expression in postfix form

  2. implement recursion

  3. convert a given arithmetic expression in infix form to its equivalent postfix form

  4. allocate resources (like CPU) by the operating system
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Stacks are LIFO structures used for expression evaluation, recursion, and syntax parsing. CPU scheduling typically uses queues (like round-robin) or priority queues, not stacks.

Multiple choice

HIPO charts facilitate

  1. analysis of modules

  2. top - down design

  3. organizational structure

  4. none of the above
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

HIPO (Hierarchy plus Input-Process-Output) charts are a design tool used to represent the functional hierarchy of a system, supporting a top-down design approach.