This document provides a comprehensive overview of algorithms in computing, explaining their role, design, and fundamental operations such as exchanging values, counting, and computing factorials. It outlines the steps involved in problem solving, including definition, analysis, design, coding, testing, and maintenance. Additionally, it defines algorithms, highlights their characteristics and advantages, and provides examples of algorithms for common tasks.

1. UNIT - 1
Introduction: The Role of Algorithms in Computing, Algorithms
as a technology, Analyzing algorithms, Designing algorithms,
Growth of Functions, Asymptotic notation, Standard notations
and common functions.
Fundamental Algorithms: Exchanging the values of two
variables, Counting, Summation of a set of numbers, Factorial
Computation, Generating of the Fibonacci sequence, Reversing
the digits of an integer, Character to number conversion.

2. Problem solving
•It is a systematic approach to find and implement the solution to a
problem.
Program
•It is a set of instructions written in computer languages
Software
•It is a collection of computer program (or) data and instructions.
•It is responsible for controlling, integration and managing hardware
components and perform specific tasks.

3. Classifications of software
System software
•It is a set of one or more programs that manage and support
a computer system hardware and its data processing
activities.
•Ex: Operating system, Compilers, Assemblers
Application software
•It is a set of one or more programs, designed to solve a
specific problem or a specific task.
•Ex: Ms-Word ,Ms-Excel, Ms-Powerpoint

4. Steps in Problem Solving
1. Problem Definition
2. Problem Analysis
3. Design
4. Coding
5. Testing
6. Maintenance

5. 1. Problem Definition
•To solve a problem, the first step is to
identify and define the problem.
•The problem must be stated clearly,
accurately and precisely.
•Ex: Find largest of three numbers

6. 2. Problem Analysis
The problem analysis helps in designing and coding for that
particular problem.
1. Input specifications
•The number of inputs and what forms the input are available
2.Output specifications
•The number of outputs and what forms the output should be
displayed.
Ex:
•input – a,b,c
•output – a (or) b (or) c

7. 3. Designing a program
Algorithms
•Algorithm - step by step procedure of solving a problem
Flowcharts
•Flowcharts – It is the graphical representation of the
algorithm.

8. 4. Coding
• Writing instructions in a particular language to solve a
problem.
5. Testing a Program
• After writing a program, programmer needs to test the
program for completeness, correctness, reliability and
maintainability.
• Unit testing
• Program Testing
• Verification Testing
• Validation Testing

9. 6. Maintaining the program
•It means periodic review of the
programs and modifications based on
user requirements.

10. What is an Algorithm?
•In computer programming terms, an algorithm is a set of
well-defined instructions to solve a particular problem. It
takes a set of input(s) and produces the desired output.
For example,
•An algorithm to add two numbers:
1. Take two number inputs
2. Add numbers using the + operator
3. Store the result
4. Display the result
Hint:
Need of the Algorithm:
Algorithms are used to solve problems or automate tasks in a systematic and efficient manner. They are a set of
instructions or rules that guide the computer or software in performing a particular task or solving a problem.

11. Qualities of a Good Algorithm
•Input and output should be defined
precisely.
•Each step in the algorithm should be clear
and unambiguous.
•Algorithms should be most effective among
many different ways to solve a problem.
•An algorithm shouldn't include computer
code. Instead, the algorithm should be
written in such a way that it can be used in
different programming languages.

12. Characteristics of an algorithm
The characteristics of an algorithm are
•(i) Algorithm must have finite number of steps.
•(ii) No instructions should be repeated.
•(iii) An algorithm should be simple.
•(iii) An algorithm must take atleast one or more
input values.
•(iv) An algorithm must provide atleast one or more
output values.

13. Characteristics of an algorithm

14. Advantages
•Algorithms are very easy to
understand.
•Algorithm is programming language
independent.
•Algorithm makes the problem simple,
clear, correct.

15. The Role of Algorithms
• Algorithms play a crucial role in computing by providing
a set of instructions for a computer to perform a specific
task.
• They are used to solve problems and carry out tasks in
computer systems, such as sorting data, searching for
information, image processing, and much more.
• An algorithm defines the steps necessary to produce
the desired outcome, and the computer follows the
instructions to complete the task efficiently and
accurately.

16. Role of Algorithm in Applications

17. Role of Algorithm in Computing

18. Role of Algorithm in Networking

19. Algorithm to Add two numbers entered by
the user
• Step 1: Start
• Step 2: Declare variables num1, num2 and sum.
• Step 3: Read values num1 and num2.
• Step 4: Add num1 and num2 and assign the result to sum.
• sum←num1+num2
• Step 5: Display sum
• Step 6: Stop

20. Algorithm for Swapping
two numbers using third
variable:
Step 1: Declare a variable a,b
and c as integer;
Step 2: Read two numbers a and
b;
Step 3: c=a;
Step 4: a=b;
Step 5: b=c;
Step 6: Print a and b
STEP 1: START
STEP 2: ENTER A, B
STEP 3: PRINT A, B
STEP 4: A = A + B
STEP 5: B= A - B
STEP 6: A =A - B
STEP 7: PRINT A, B
STEP 8: END
Algorithm for Swapping two
numbers without using third
variable:

21. Algorithm to find Summation of a set of
numbers
Step 1: Start
Step 2: Read the number n
Step 3: Calculate the sum of n natural number, sum = n * (n + 1) / 2
Step 4: Display sum
Step 5: End

22. Algorithm to find count of numbers of digits
in a number
• Step 1: Declare variable a and n; //n variable is used for counting
• Step 2: Read number a;
• Step 3: while(a not equal 0)
• a=a/10;
• n=n+1;
• end
• Step 4: Print n;
• Step 5: End

23. Algorithm to Find the largest number among
three numbers
Step 1: Start
Step 2: Declare variables a,b and c.
Step 3: Read variables a,b and c.
Step 4: If a > b
If a > c
Display a is the largest number.
Else
Display c is the largest number.
Else
If b > c
Display b is the largest number.
Else
Display c is the greatest number.
Step 5: Stop

24. Algorithm to Find the factorial of a number
Step 1: Start
Step 2: Declare variables n, fact and i.
Step 3: Initialize variables
fact← 1
i ← 1
Step 4: Read value of n
Step 5: Repeat the steps until i = n
5.1: fact ← fact*i
5.2: i ← i+1
Step 6: Display fact
Step 7: Stop

25. Algorithm 6: Find the Fibonacci series
• Step 1: Start
• Step 2: Declare variable a, b, c, n, i
• Step 3: Initialize variable a=0, b=1 and i=2
• Step 4: Read n from user
• Step 5: Print a and b
• Step 6: Repeat until i<=n :
Step 6.1: c=a+b
Step 6.2: print c
Step 6.3: a=b, b=c
Step 6.4: i=i+1
• Step 7: Stop

26. Algorithm to Reversing the digits of an
integer
• Step 1: Declare variable n, rev and rem as integer;
• Step 2: Read the number n;
• Step 3: while n not equal 0
{
rem=n%10;
rev=rev * 10 + rem;
n=n/10;
}
• Step 4: Print rev

33. GREATEST OF THREE
NUMBERS

34. FACTORIAL OF GIVEN
NUMBER

35. FIBONACCI SERIES

36. REVERSE THE GIVEN
NUMBER

38. Algorithms as a technology

39. Analysing Algorithms

44. Designing algorithms