Algorithm and Flowchart Notes for SSC Exams
Rahul Kumar
SSC Exam Expert & Content Editor
In this note
- 1.What Is an Algorithm?
- 2.Properties of a Good Algorithm
- 3.What Is a Flowchart?
- 4.Flowchart Symbols
- 5.Three Programming Constructs
- 6.Pseudocode
- 7.Example 1: Add Two Numbers
- 8.Example 2: Find the Larger of Two Numbers
- 9.Algorithm vs Flowchart
- 10.From Algorithm to Program
- 11.Quick Tips
- 12.Quick Revision Points
- 13.Practice Questions With Answers
- 14.How to Practise This Chapter
- 15.Frequently Asked Questions
PDF Notes: Algorithm and Flowchart Notes for SSC Exams
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Before a computer program is written, the problem is first planned with an algorithm and a flowchart. This topic is asked in the SSC Computer Knowledge section in the form of definitions, the symbols of a flowchart and simple examples. These algorithm and flowchart notes for SSC explain the properties, the symbols, the three programming constructs and the examples in simple language with practice questions.
What Is an Algorithm?
- An algorithm is a finite set of step-by-step instructions to solve a problem.
- It is written in simple language and is independent of any programming language.
- The word algorithm comes from the name of the Persian scholar Al-Khwarizmi.
Properties of a Good Algorithm
| Property | Meaning |
|---|---|
| Finiteness | It must end after a limited number of steps |
| Definiteness | Every step must be clear and unambiguous |
| Input | It has zero or more inputs |
| Output | It gives at least one output |
| Effectiveness | Every step must be simple and possible to do |
What Is a Flowchart?
A flowchart is a picture of an algorithm that uses standard symbols joined by arrows. It shows the flow of the steps and decisions, and it is easy to understand and to check.
Flowchart Symbols
| Symbol | Name | Use |
|---|---|---|
| Oval | Terminator | Start and end of the flowchart |
| Parallelogram | Input / Output | To read data or to show results |
| Rectangle | Process | Calculation or an instruction |
| Diamond | Decision | Yes/No or True/False question with two outputs |
| Arrow | Flow line | Shows the direction of the flow |
| Circle | Connector | Joins two parts of a flowchart, on the same or another page |
Three Programming Constructs
| Construct | Meaning | Example |
|---|---|---|
| Sequence | Steps are done one after the other | Read A, read B, add, print |
| Selection (decision) | A choice is made with a condition | If marks are 33 or more, print Pass; else print Fail |
| Iteration (loop) | Steps are repeated while a condition is true | Print the numbers from 1 to 10 |
Pseudocode
Pseudocode is a way of writing an algorithm in simple English-like statements that look like a program but follow no strict syntax. It is easier to write than a program and helps in planning.
Example 1: Add Two Numbers
- Start.
- Read the numbers A and B.
- Calculate SUM = A + B.
- Print SUM.
- Stop.
Example 2: Find the Larger of Two Numbers
- Start.
- Read A and B.
- If A is greater than B, print A.
- Otherwise, print B.
- Stop.
In the flowchart, the question "A greater than B?" is placed in a diamond with two arrows, Yes and No.
Algorithm vs Flowchart
| Point | Algorithm | Flowchart |
|---|---|---|
| Form | Written steps in words | Picture with symbols |
| Understanding | Needs reading | Easy to see the flow |
| Use | To plan the logic | To show the logic and the decisions |
From Algorithm to Program
- Define the problem.
- Write the algorithm and draw the flowchart.
- Write the program in a programming language.
- Translate it with a compiler or interpreter.
- Test, find errors and remove them (debugging).
- Document and maintain the program.
- A syntax error is a mistake in the rules of the language, and a logical error is a mistake in the logic, which gives a wrong result without any error message.
Quick Tips
- Remember the symbols: oval for start and stop, parallelogram for input and output, rectangle for process and diamond for decision.
- Learn the five properties of an algorithm with one word each.
- Remember that a decision symbol has two outputs.
- Learn the difference between a syntax error and a logical error.
Quick Revision Points
- An algorithm is a finite set of steps to solve a problem.
- The diamond symbol is used for a decision.
- The parallelogram is used for input and output.
- The three constructs are sequence, selection and iteration.
- Pseudocode is an English-like way to write an algorithm.
Practice Questions With Answers
- Which symbol is used for a decision in a flowchart?
Answer: Diamond - Which symbol is used for input and output?
Answer: Parallelogram - Which symbol shows the start and end of a flowchart?
Answer: Oval (terminator) - What is a finite set of steps to solve a problem called?
Answer: Algorithm - Which flowchart symbol is used for a calculation?
Answer: Rectangle (process) - What are the three programming constructs?
Answer: Sequence, selection and iteration - What is repetition of steps called?
Answer: Iteration (loop) - What is a mistake in the rules of the language called?
Answer: Syntax error - What is the process of finding and removing errors called?
Answer: Debugging - What is a pictorial form of an algorithm called?
Answer: Flowchart
How to Practise This Chapter
Write the algorithm and draw the flowchart of five simple problems, such as the sum of two numbers, the larger of two numbers and the factorial of a number. Then solve questions from our practice papers and the previous year papers page. Read the previous chapter, Artificial Intelligence and Machine Learning, and see all topics on the Computer Knowledge notes page. Also read Computer Languages and Translators.
Frequently Asked Questions
What is an algorithm?
An algorithm is a step-by-step set of instructions to solve a problem, and it has a limited number of steps.
What is a flowchart?
A flowchart is a diagram that shows an algorithm with symbols and arrows.
What are the properties of an algorithm?
An algorithm must be finite, definite, effective, and it must have zero or more inputs and at least one output.
Which symbol is used for a decision in a flowchart?
The diamond symbol is used for a decision, and it has two outputs, such as yes and no.
Which symbol is used for input and output?
The parallelogram is used for input and output.
What is pseudocode?
Pseudocode is a way of writing an algorithm in simple English-like statements, without the strict rules of a programming language.
What are the three programming constructs?
They are sequence, selection (decision) and iteration (loop).
What is the difference between an algorithm and a flowchart?
An algorithm is written in words, and a flowchart shows the same logic with symbols.
What is a syntax error?
A syntax error is a mistake in the rules of the programming language, and the program does not run until it is removed.
What is a logical error?
A logical error is a mistake in the logic of the program, which gives a wrong result without any error message.
What is debugging?
Debugging is the process of finding and removing errors from a program.
How many questions come from algorithm and flowchart in SSC exams?
Usually one question comes from this topic in SSC Computer Knowledge papers, but the number changes from year to year.
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Rahul Kumar
SSC Exam Expert & Content Editor
Rahul is a senior SSC exam strategist with 8+ years of experience helping aspirants crack CGL, CHSL and MTS exams. He writes in-depth notification breakdowns, exam pattern guides and preparation strategies.