DATA STRUCTURES AND ALGORITHMS | FROM QUESTION
TO PERFECTION| STUDY WITH CONFIDENCE!
Course Code:
Course Title: DATA STRUCTURES AND ALGORITHMS.
Programme:
Academic Year: 2026/2027
Duration: 2 Hours
Total Marks: 100
Candidate Instructions:
1) Write your Registration Number on every answer booklet used.
2) Answer ALL questions in Section A and ANY TWO (2) questions in
Section B.
3) Read each question carefully before answering.
4) Begin each question on a new page.
5) The marks for each question are indicated in brackets.
6) This paper consists of several printed pages, including this page.
7) Ensure your copy is complete before the examination begins.
8) Unauthorized materials and communication with other candidates are not
permitted.
Turn Over.
APPHIA – Crafted with Care and Precision for Academic Excellence.
1
,Why do we need a high level language? Answer: High-level languages encourage you to think
more about the problem domain and less about the execution platform. There is less ceremony,
so you can spend more time on stuff that actually brings you value. Money. Cheaper developers,
faster development speeds, and less bugs equal more money.
A high level language is easier to code in and therefore less error prone.
Program Answer: A set of instructions for the computer to perform a task.
It can be stored in memory or downloaded from the internet.
when do you use float instead of double? Answer: Though both Java float and Double can
represent floating-point numbers, we can consider a couple of things to choose between Java
float and double.
Though both Java float vs Double is approximate types, use double if you need more precise
and accurate results. Use float if you have memory constraint because it takes almost half as
much space as double. If your numbers cannot fit in the range offered by float, then use double.
Though be careful with floating-point calculation and representation, don't use double or float
for monetary calculation, instead use Big Decimal.
What is selection? Answer: Making the program behave differently each time it runs.
the switch statement Answer: In computer programming languages, a switch statement is a type
of selection control mechanism used to allow the value of a variable or expression to change the
control flow of program execution via search and map.
Designing algorithms Answer: A strategy to solve a problem in terms of
1. the actions to be executed
2. the order in which the actions are to be executed
when do we use a for loop? Answer: generally used when the number of repetitions or iterations
is known in advance.
For example, you know there are 10 students in a class and you want to calculate the average
mark for them all.
What to do when the number of loops is not fixed? Answer: Use a while loop
What is the difference between a while loop and a for loop? Answer: A while loop causes the
code inside it to be repeated until some condition is satisfied.
A for loop is repeated for a fixed number of iterations.
Asymptotic Notation Answer: Asymptotic notations are the mathematical notations used to
describe the running time of an algorithm when the input tends towards a particular value or a
limiting value.
For example: In bubble sort, when the input array is already sorted, the time taken by the
algorithm is linear i.e. the best case.
APPHIA – Crafted with Care and Precision for Academic Excellence.
2
, But, when the input array is in reverse condition, the algorithm takes the maximum time
(quadratic) to sort the elements i.e. the worst case.
When the input array is neither sorted nor in reverse order, then it takes average time. These
durations are denoted using asymptotic notations.
There are mainly three asymptotic notations:
Big-O notation
Omega notation
Theta notation
What types of trees do you know? Answer: Free trees
Binary
Positional trees
Rooted trees
Ordered trees
Define a free tree Answer: In a free tree there's no designated root vertex.
You can make a free tree into a rooted one by choosing any of its vertices to be the root.
Define rooted tree Answer: In graph theory, the basic definition of a tree is that it is a connected
graph without cycles. This definition does not use any specific node as a root for the tree. A
rooted tree introduces a parent — child relationship between the nodes and the notion of depth
in the tree.
Roughly and visually, adding a root to a tree just corresponds to grabbing one of the nodes of
the tree and hanging the tree with this node. Once the tree is hanged, each node has a depth
related to its height, a parent to which it is suspended and several children which hang from this
node.
what is a binary and positional tree Answer: a binary tree is a tree data structure in which each
node has at most two children, which are referred to as the left child and the right child.
A tree is either empty or consists of a node containing a label value and an indexed sequence of
zero or more children, each a positional tree. If every node has two positions, we have a binary
tree and the children are its left and right subtrees. Again, nodes are the parents of their non-
empty children.
How can you distinguish between binary trees and ordered trees Answer: An ordered tree is an
oriented tree in which the children of a node are somehow "ordered."
What sorting algorithms do you know? Answer: Quicksort
Heapsort
APPHIA – Crafted with Care and Precision for Academic Excellence.
3
TO PERFECTION| STUDY WITH CONFIDENCE!
Course Code:
Course Title: DATA STRUCTURES AND ALGORITHMS.
Programme:
Academic Year: 2026/2027
Duration: 2 Hours
Total Marks: 100
Candidate Instructions:
1) Write your Registration Number on every answer booklet used.
2) Answer ALL questions in Section A and ANY TWO (2) questions in
Section B.
3) Read each question carefully before answering.
4) Begin each question on a new page.
5) The marks for each question are indicated in brackets.
6) This paper consists of several printed pages, including this page.
7) Ensure your copy is complete before the examination begins.
8) Unauthorized materials and communication with other candidates are not
permitted.
Turn Over.
APPHIA – Crafted with Care and Precision for Academic Excellence.
1
,Why do we need a high level language? Answer: High-level languages encourage you to think
more about the problem domain and less about the execution platform. There is less ceremony,
so you can spend more time on stuff that actually brings you value. Money. Cheaper developers,
faster development speeds, and less bugs equal more money.
A high level language is easier to code in and therefore less error prone.
Program Answer: A set of instructions for the computer to perform a task.
It can be stored in memory or downloaded from the internet.
when do you use float instead of double? Answer: Though both Java float and Double can
represent floating-point numbers, we can consider a couple of things to choose between Java
float and double.
Though both Java float vs Double is approximate types, use double if you need more precise
and accurate results. Use float if you have memory constraint because it takes almost half as
much space as double. If your numbers cannot fit in the range offered by float, then use double.
Though be careful with floating-point calculation and representation, don't use double or float
for monetary calculation, instead use Big Decimal.
What is selection? Answer: Making the program behave differently each time it runs.
the switch statement Answer: In computer programming languages, a switch statement is a type
of selection control mechanism used to allow the value of a variable or expression to change the
control flow of program execution via search and map.
Designing algorithms Answer: A strategy to solve a problem in terms of
1. the actions to be executed
2. the order in which the actions are to be executed
when do we use a for loop? Answer: generally used when the number of repetitions or iterations
is known in advance.
For example, you know there are 10 students in a class and you want to calculate the average
mark for them all.
What to do when the number of loops is not fixed? Answer: Use a while loop
What is the difference between a while loop and a for loop? Answer: A while loop causes the
code inside it to be repeated until some condition is satisfied.
A for loop is repeated for a fixed number of iterations.
Asymptotic Notation Answer: Asymptotic notations are the mathematical notations used to
describe the running time of an algorithm when the input tends towards a particular value or a
limiting value.
For example: In bubble sort, when the input array is already sorted, the time taken by the
algorithm is linear i.e. the best case.
APPHIA – Crafted with Care and Precision for Academic Excellence.
2
, But, when the input array is in reverse condition, the algorithm takes the maximum time
(quadratic) to sort the elements i.e. the worst case.
When the input array is neither sorted nor in reverse order, then it takes average time. These
durations are denoted using asymptotic notations.
There are mainly three asymptotic notations:
Big-O notation
Omega notation
Theta notation
What types of trees do you know? Answer: Free trees
Binary
Positional trees
Rooted trees
Ordered trees
Define a free tree Answer: In a free tree there's no designated root vertex.
You can make a free tree into a rooted one by choosing any of its vertices to be the root.
Define rooted tree Answer: In graph theory, the basic definition of a tree is that it is a connected
graph without cycles. This definition does not use any specific node as a root for the tree. A
rooted tree introduces a parent — child relationship between the nodes and the notion of depth
in the tree.
Roughly and visually, adding a root to a tree just corresponds to grabbing one of the nodes of
the tree and hanging the tree with this node. Once the tree is hanged, each node has a depth
related to its height, a parent to which it is suspended and several children which hang from this
node.
what is a binary and positional tree Answer: a binary tree is a tree data structure in which each
node has at most two children, which are referred to as the left child and the right child.
A tree is either empty or consists of a node containing a label value and an indexed sequence of
zero or more children, each a positional tree. If every node has two positions, we have a binary
tree and the children are its left and right subtrees. Again, nodes are the parents of their non-
empty children.
How can you distinguish between binary trees and ordered trees Answer: An ordered tree is an
oriented tree in which the children of a node are somehow "ordered."
What sorting algorithms do you know? Answer: Quicksort
Heapsort
APPHIA – Crafted with Care and Precision for Academic Excellence.
3
