Lesson 2 - Algorithm and Flowcharting.pdf

In the realm of computer science, algorithms and flowcharts serve as the foundational tools for problem-solving and program development. An algorithm is a step-by-step procedure for accomplishing a specific task, while a flowchart is a visual representation of an algorithm using various shapes to symbolize different actions or decisions. Together, they provide a structured and systematic approach to designing and implementing effective solutions.

Algorithms are the heart of programming. They define the logic and sequence of operations that a computer must follow to achieve a desired outcome. Whether it's sorting a list of numbers, searching for a specific item in a database, or calculating complex mathematical equations, algorithms provide the blueprint for how these tasks should be executed. A well-designed algorithm is efficient, accurate, and easy to understand.

Flowcharts, on the other hand, offer a visual representation of an algorithm. They use various shapes to depict different types of actions or decisions. For example, a rectangle typically represents a process or action, a diamond represents a decision point, and an oval represents the start or end of the flowchart. By connecting these shapes with arrows, flowcharts provide a clear and concise overview of the algorithm's flow.

The relationship between algorithms and flowcharts is symbiotic. Algorithms provide the underlying logic, while flowcharts offer a visual representation of that logic. By creating a flowchart before writing code, programmers can gain a better understanding of the algorithm's structure and identify potential errors or inefficiencies. Flowcharts also serve as valuable documentation tools, helping to communicate the algorithm's logic to others.

To illustrate the connection between algorithms and flowcharts, let's consider a simple example: calculating the factorial of a number. The factorial of a number n is the product of all positive integers less than or equal to n. Here's a basic algorithm for calculating the factorial:  

Start with a variable factorial initialized to 1.
If the number is 0 or 1, the factorial is 1.
Otherwise, multiply factorial by the current number and decrement the number.
Repeat steps 3 and 4 until the number reaches 0.
Return the final value of factorial.
A corresponding flowchart for this algorithm might look like this:

Opens in a new window
www.enggstudy.com
flowchart for calculating the factorial of a number

As you can see, the flowchart visually represents the steps outlined in the algorithm. The rectangle shapes indicate processes (e.g., initializing factorial, multiplying, decrementing), while the diamond shape represents the decision point of checking if the number is 0 or 1.

While flowcharts are a valuable tool for understanding and communicating algorithms, they have their limitations. For complex algorithms, flowcharts can become cumbersome and difficult to follow. In such cases, pseudocode, a semi-formal language that comb

3. ▪
▪
▪

5. ▪
▪
▪
▪
▪

7. ▪
▪
▪
▪

12. START
birthyear, age
display
“Enter Year of Birth:”
input
birthyear
age = 2023 - birthyear
display
age
END

14. START
kilo, pound
display
“Enter Weight in
Kilogram:”
input
kilo
pound = kilo * 2.2
display
pound
END

16. START
length, width, area
display
“Enter Length:”
input
length
display
“Enter Width:”
input
width
A

17. area = length * width
display
area
A
END

18. ▪
▪
▪

19. START
num1, num2, num3, num4,
sum, product, square
display
“Enter the First
Number: ”
input
num1
display
“Enter the Second
Number: ”
input
num2
A

20. display
“Enter the Third
Number: ”
input
num3
display
“Enter the Fourth
Number: ”
input
num4
B
A
sum = num1 + num2

21. display
sum
display
square
B
product = num3 * num4
square = num2 * num2
display
product
END

22. ▪
▪
▪
▪

23. START
num1, num2, num3, num4,
cube, half, twentyp, times100
display
“Enter the First
Number: ”
input
num1
display
“Enter the Second
Number: ”
input
num2
A

24. display
“Enter the Third
Number: ”
input
num3
display
“Enter the Fourth
Number: ”
input
num4
B
A
cube = num1 * num1 * num1

25. B
half = num2 / 2
twentyp = num3 * 0.20
END
times100 = num4 * 100
display
cube
display
half
display
twentyp
display
times100

28. ▪
▪
▪
▪