Page 102 - Computer Science V2.0 Class 11

Unit II: Computational Thinking and Programming—I

4 PROBLEM SOLVING
PROBLEM SOLVING

Chapter Outline

4.1 Problem-Solving Steps 4.2 Algorithm, Flowchart, and Pseudocode

Introduction
Suppose you are driving to a destination. Suddenly, you encounter a problem—a traffic jam 100 meters away. You recall
from memory that there is an alternate route. You realize that, although the alternative route is longer, it is still likely
to take less time than getting stuck in a traffic jam. So, you take a U-turn that takes you to an alternative route. Thus,
your problem-solving skills enabled you to avoid traffic congestion and reach your destination faster. Consider another
scenario: Your car breaks down while you are driving, and you call a 24-hour car helpline to arrange for a mechanic.
On arrival, the mechanic first checks the fuel status. As he finds enough fuel in the tank, he checks whether the battery
has drained. As he discovers the battery is not drained, he checks for engine failure using an onboard diagnostic (OBD)
module that he has brought with him. The OBD module indicates that the engine is getting too hot. Knowing this, he
fixes the problem, and the car runs again.
In solving the first problem, you made use of your own problem-solving skills. To solve the second problem, you needed
a car mechanic. The mechanic, in turn, needed a specialized diagnostic module, which is a piece of hardware with
software built in. We just noted that the mechanic knew the procedure (also called an algorithm) to set the car right.
He also realized his limitations. So, he brought with him an OBD module to assist him. He could solve the problem of
car failure because he knew how to use the OBD module in an interactive manner. A computer is a great tool to solve a
large number of problems. However, to use a computer to solve a problem, you need to develop problem-solving skills
using computers. Indeed, an OBD module is a specialized computer. In this chapter, we will study the steps involved in
solving a problem using a computer.

4.1 Problem-Solving Steps

Given a trivial problem, one can visualize the solution instantly. But a systematic approach is needed to solve a
complicated problem. If you want your friend to help you solve a problem, you must define it completely and
unambiguously. If the problem description is ambiguous, it is highly unlikely that your friend will be able to provide
you with the desired solution. In the same way, the first step in using a computer to solve a problem is to describe it
clearly. Next, one analyzes the problem and develops a solution strategy (called an algorithm). Finally, code is written
to implement the algorithm.

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