PROBLEM
S O LV I N G
Chap 4
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P ROBL EM S OLVI NG CYC LE
• Identify and analyse the problem.
• Find its solution and develop algorithm of the solution.
• Code the solution in a programming language.
• Test and debug the coded solution.
Finally implement and maintain it.
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4. Testing 1.Analysis
• Perform testing
• Analyse the probel
and debugging
3. Coding 2. Design
• Coding of the • Find solution and
solution develop algorithm
STEPS IN PROBLEM SOLVING CYCLE
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S UB -ST EPS OF PROB LE M SOLVI N G CYC L E
Analyse the Problem
• Understand the problem well
• Analyse the problem
Developing the Algorithm
• Think of possible solution
• Follow Modular Approach while designing most appropriate solution
• Identify operation for solution
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S UB -ST EPS OF PROB LE M SOLVI N G CYC L E
Coding
• Code program using appropriate control structures.
Testing and Debugging
• Test debug your program
• Complete your documentation.
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S UB -ST EPS OF PROB LE M SOLVI N G CYC L E
Implement and maintain
•Implement your code
•Maintain your program
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• The process of breaking down
a big or complex problem into
PROBLEM a set of smaller sub-
SO LV ING U SING process in order to
DECOMPOSITION understand a problem or
situation better, is known as
decomposition steps.
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D E C O M P O S I T I O N I N V O LV E S
Dividing a task into a sequence of Identifying elements or part of
subjects. a complex system.
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Big Problem
Part 1 Part 2
DECOMPOSITION of Problem of Problem
Sub- Sub- Sub- Sub-
Program 1 Program 2 Problem 3 Problem 4
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• Decomposing a problem into smaller
sub-programs
NEED FOR
is important because large problems
DECOMPOSITION are disproportionately harder to
solve than smaller problems.
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• The set of rules that defines
how a particular problem can
be solved in finite number of
DESIGNING steps is known as algorithm.
ALGORITHMS • An algorithm is composed of
a finite set of steps, each of
which may require one or
more operations.
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Precision — the steps are precisely stated or
defined.
Uniqueness — results of each step are uniquely
defined and only depend on the input and the
result of the preceding steps.
CHARACTERISTICS
Finiteness — the algorithm always stops after a
OF A GOOD finite number of steps.
ALGORITHM
Input — the algorithm receives some input.
Output — the algorithm produces some output.
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COMPONENTS OF AN ALGORITHM
• While writing an algorithm, it is required to clearly identify the following:
The input to be taken from the user
Processing or computation to be performed to get the desired result
The output desired by the user
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E X AM PL E - A LG O R I T H M TO FI ND S Q UAR E
OF A NUMBER
Step 1 Input a number and store it to num
Step 2 Compute num * num and store it in square
Step 3 Print square
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FLOW CHART
A flowchart is a visual representation
of an algorithm.
A flowchart is a diagram made up
of boxes, diamonds and other
shapes, connected by arrows.
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SYMBOLS
Symbols Functions Descriptions
Also called “Terminator”
Start/End symbol. It indicates where
the flow starts and ends.
Also called “Action
Symbol,” it represents a
Process
process, action, or a single
step.
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SYMBOLS
Symbols Functions Descriptions
A decision or branching point, usually a
yes/no or true/ false question is asked,
Decision
and based on the answer, the path gets
split into two branches.
Also called data symbol, this
Input/Output parallelogram shape is used to input or
output data
Connector to show order of flow between
Arrow
shapes.
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START
GET
A&B
FLOWCHART TO
ADD TWO NUMBERS C=A+B
PRINT C
STOP
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• Pseudocode is an informal
way of describing the steps of
a program's solution without
PSEUDOCODE using any strict programming
language syntax or underlying
technology considerations.
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EXAMPLE
If students's marks is greater than or equal to 50
display "Passed"
Else
display "Failed"
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