Introduction to problem solving Computer Science Class 11 Notes

This article – introduction to problem solving Computer Science Class 11 offers comprehensive notes for Chapter 4 of the CBSE Computer Science Class 11 NCERT textbook.

Introduction to problem solving Computer Science class 11

Computers, mobiles, the internet, etc. becomes our essentials nowadays for our routine life. We are using the to make our tasks easy and faster.

For example, earlier we were going to banks and standing in long queues for any type of transaction like money deposits or withdrawals. Today we can do these tasks from anywhere without visiting banks through internet banking and mobiles.

Basically, this was a complex problem and solved by a computer. The system was made online with the help of computers and the internet and made our task very easy.

This process is termed “Computerisations”. The problem is solved by using software to make a task easy and comfortable. Problem solving is a key term related to computer science.

The question comes to your mind how to solve a complex problem using computers? Let’s begin the article introduction to problem-solving Computer Science 11.

Introduction to problem solving Computer Science Class 11 – Steps for problem solving

“Computer Science is a science of abstraction -creating the right model for a problem and devising the appropriate mechanizable techniques to solve it.”

Solving any complex problem starts with understanding the problem and identifying the problem.

Suppose you are going to school by your bicycle. While riding on it you hear some noise coming from it. So first you will try to find that from where the noise is coming. So if you couldn’t solve the problem, you need to get it repaired.

The bicycle mechanic identifies the problem like a source of noise, causes of noise etc. then understand them and repair it for you.

So there are multiple steps involved in problem-solving. If the problem is simple and easy, we will find the solution easily. But the complex problem needs a few methods or steps to solve.

So complex problem requires some tools, a system or software in order to provide the solution. So it is a step-by-step process. These steps are as follows:

  1. Analysing the problem
  2. Developing an algorithm
  3. Coding
  4. Testing and debugging

The first step in the introduction to problem solving Computer Science Class 11 is analyzing the problem.

Analysing the problem

When you need to find a solution for a problem, you need to understand the problem in detail. You should identify the reasons and causes of the problem as well as what to be solved.

So this step involves a detailed study of the problem and then you need to follow some principles and core functionality of the solution.

In this step input and output, elements should be produced.

The second step for introduction to problem solving Computer Science class 11 is developing an algorithm.

Developing an algorithm

An algorithm is a step-by-step process of a solution to a complex problem. It is written in natural language. An algorithm consists of various steps and begins from start to end. In between input, process and output will be specified. More details we will cover in the next section.

In short, the algorithm provides all the steps required to solve a problem.

For example:

Finding the simple interest, you need to follow the given steps:

  1. Gather required information and data such as principle amount, rate of interest and duration.
  2. Apply the formula for computing simple interest i.e. si=prn/100
  3. Now store the answer in si
  4. Display the calculated simple interest

In the above example, I have started and completed a task in a finite number of steps. It is completed in 4 finite steps.

Why algorithm is needed?

The algorithm helps developers in many ways. So it is needed for them for the following reasons:

  1. It prepares a roadmap of the program to be written before writing code.
  2. It helps to clearly visualise the instructions to be given in the program.
  3. When the algorithm is developed, a programmer knows the number of steps required to follow for the particular task.
  4. Algorithm writing is the initial stage (first step) of programming.
  5. It makes program writing easy and simple.
  6. It also ensures the accuracy of data and program output.
  7. It increases the reliability and efficiency of the solution.

Characteristics of a good algorithm

The characteristics of a good algorithm are as follows:

  1. It starts and ends with a finite number of steps. Therefore the steps are precisely stated or defined.
  2. In the algorithm, the result of each step is defined uniquely and based on the given input and process.
  3. After completion of the task, the algorithm will end.
  4. The algorithm accepts input and produces the output.

While writing the algorithm the following things should be clearly identified:

  1. The input required for the task
  2. The computation formula or processing instructions
  3. The result

After writing the algorithm, it is required to represent it. Once the steps are finalised, it is required to be represented logically. This logical representation of the program clearly does the following:

  1. Clears the logic of the program
  2. The execution of the program

The algorithm is steps written in the form of text. So it is difficult to read sometimes. So if it is represented in pictorial form it would be better for analysis of the program.

The flowchart is used to represent the algorithm in visual form.

Flowchart – Visual representation of an algorithm

A flowchart is made of some symbols or shapes like rectangles, squares, and diamonds connected by arrows. Every shape represents each step of an algorithm. The arrow basically represents the order or link of the steps.

The symbols used in the flow chart are as follows:

flow chart symbols introduction to problem solving computer science class 11

Coding is an essential part of the introduction to problem solving ComputerScience11.


  • It is pronounced as soo-doh-kohd
  • It is one of the ways of representing algorithms in a systematic way
  • The word pseudo means not real, therefore pseudocode means not real code
  • It is non-formal language, that helps programmers to write code
  • It is written in human understandable language
  • It cannot be directly read by computers
  • There is no specific standard or way of writing pseudocode is there


When an algorithm is prepared, the next step is writing code. This code will be written in a specific programming language. The code follows certain rules and regulations of the programing language and provides solutions.

When coding is done you need to maintain it with proper documentation as well. The best practices for coding procedures must be followed. Because this code can be reviewed a number of times for further development and upgradation.

Testing and debugging

Let’s understand this step with a simple example!!

When your mother prepares a cake at your home, she will give peace of cake to someone before serving it to check the taste of the cake, right!!! If anything is needed like sugar or softness or hardness should be improved she will decide and do the improvement.

Similarly after writing code testing and debugging are required to check the software whether is providing the solution in a good manner not.

Have look at this also: Computer Science Class XI

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