Steps in Problem Solving and IPO_Sequence

DC024

Topic 1: Problem Solving

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SEMESTER II SESSION 2018/2019

1.0 Problem Solving

1.1 Steps in Problem Solving
1.2 Problem Analysis
1.3 Design a Solution

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Learning Outcome:

At the end of this topic, students should be able to:

(a) List five steps in problem solving.

(b) Identify input, process and output from a

given problem.

(c) Define pseudocode and flowchart.

(d) Solve a given problem using pseudocode -

Sequence

(e) Solve a given problem using flowchart - 3
Sequence

Learning Outcome:

At the end of this topic, students should be able to:

(e) Solve a given problem using pseudocode -

Selection

(f) Solve a given problem using flowchart -

Selection

(g) Solve a given problem using pseudocode -

Repetition

(h) Solve a given problem using flowchart - 4
Repetition

[ Introduction ]

This subtopic introduces
you to the process
that programmers
follow when solving
problems that require
a computer solution.

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[ Introduction ]

Thing to Ponder....

Computers are NOT intelligent or telepathic

 Computers do what we tell them to do.

They don't do anything by themselves.

 We must clearly tell a computer what to do in a

step by step manner using a programming language.

 Computers are just electronic devices that have the
power to perform difficult tasks but they do not

'KNOW' what to do.

 Programmers tell the computers what to do by

writing programs. 6

[ Intro – Solving Everyday Problems ]

Scenario:

You are taking a test and your
friend behind you asks
you for help.

He/She wants to know what
you put

for question number two.
What could you do?

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[ Steps in Problem Solving ]

Five (5) steps in problem solving:

(1) Problem Analysis
(2) Design a Solution
(3) Implementation
(4) Testing
(5) Documentation

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[ Steps in Problem Solving ]

(1) Problem Analysis
• State the problem clearly.
• Identify input, process and output based
on the problem.

(2) Design a Solution
• Prepare an algorithm (pseudocode &

flowchart) for its solution.
• Write step-by-step procedure and then

verify that the algorithm solves the

problem as intended.

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[ Steps in Problem Solving ]

(3) Implementation
• Coding/Programming is the process of
translating the algorithm into the
syntax of a given programming
language.

(4) Testing
• Testing means running the program,
executing all its instructions/functions,
and testing the logic by entering sample
data to check the output.

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[ Steps in Problem Solving ]

(5) Documentation

• All of the flowcharts, messages,
algorithms, lines of code, and the user
manuals are part of this documentation.

• Internal documentation is used by other
programmers to help them know why
you did something a certain way or tell
them how you wrote a program.

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[ Steps in Problem Solving ]

(5) Documentation
External documentation includes user
manuals and anything that is not the
actual code or is art of the listing.

This should also include materials
that are placed on a website such as
FAQs (frequently asked questions).

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[ Problem Analysis ]

• Input Process Output (IPO) analysis is
used to analyze problems and develop
algorithms.

• Used to organize and summarize the
results of a problem analysis.

• It shows where in the solution the

processing takes place. 13

[ Problem Analysis ]

It can also be represent using IPO chart

Input Process Output

Information that How the input Information to be
displayed to the
must be acquired allows the user indicating the
result of the
from the user determination of problem.

before the problem the output. List names for the
output items.
can be solved.

How to compute

List names for the the output

input items. information.

Each instruction 14
begins with a verb.

2 [ IPO Analysis ] 1

Input 3 Output

Process

 Input typically  Process:  Output typically
is stated as Look for verb is stated as
nouns and use. nouns.
adjectives in
problem
specification.

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[ IPO Analysis – Tips ]

• Underline all the inputs values that must be
entered by the user.

• Underline all the outputs values that should
be generated by the program.

• Underline all the nouns, verbs and adjective.
• Write the output variable names in the output

column.
• Write the input variable names in the input

column.
• Write the processing steps in the processing

column.

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[ Analyze the Problem – Example#1 ]

Problem Statement 1:
Calculate the area of a rectangle

width
height

We can summarize the information contained
in the problem statement as follows....

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[ Analyze the Problem – Example#1 ]

Problem Analysis:
2 Input: width, height
3 Process: Calculate rectangle area
1 Output: rectangle area

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[ IPO Chart - Example#1 ]

Input Process Output

width, Calculate rectangle area rectangle
height area

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[ Analyze the Problem – Example#2 ]

Problem Statement 2:
Find the average of three numbers input by
user.

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[ Analyze the Problem – Example#2 ]

Problem Analysis:
2 Input: num1, num2, num3
3 Process: Calculate average
1 Output: average

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[ IPO Chart - Example#2 ]

Input Process Output

num1, Calculate average average
num2,
num3

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[ Analyze the Problem – Example#3 ]

Problem Statement 3:
Berjaya Concept Corporation gives a bonus to
Roy based on his sales. The bonus is 5% of the
sales. Calculate Roy's bonus.

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[ Analyze the Problem – Example#3 ]

Problem Analysis:
2 Input: sales
3 Process: Calculate bonus
1 Output: bonus

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[ IPO Chart - Example#3 ]

Input Process Output

sales Calculate bonus bonus

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[ Analyze the Problem – Question#1 ]

Problem Statement 1:
Given sides a, b, and c, finding the
perimeter of a triangle.

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[ Analyze the Problem – Question#1 ]

Problem Analysis:
Input:
Process:
Output:

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[ Analyze the Problem – Question#2 ]

Problem Statement 2:
Find the surface area of a sphere.

SA = 4 × pi × r × r

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[ Analyze the Problem – Question#2 ]

Problem Analysis:
Input:
Process:
Output:

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[ Analyze the Problem – Question#3 ]

Problem Statement 3:
Convert a measurement in millimeter
(mm) to meter (m)

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[ Analyze the Problem – Question#3 ]

Problem Analysis:
Input:
Process:
Output:

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[ Analyze the Problem – Question#4 ]

Problem Statement 4:
A government tax of 10% and service tax
of 5% will be added to the price of a set of
meal bought at MFC. Calculate the total
price that Ali has to pay for a set of meal.

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[ Analyze the Problem – Question#4 ]

Problem Analysis:
Input:
Process:
Output:

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[ Analyze the Problem – Question#5 ]

Problem Statement 5:
Calculates the Body Mass Index (BMI) for
a person.

BMI = weight / (height x height)

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[ Analyze the Problem – Question#5 ]

Problem Analysis:
Input:
Process:
Output:

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[ Analyze the Problem – Question#6 ]

Problem Statement 6:

Calculate and print the area and circumference
of a circle.

area = pi x radius x radius
circumference = 2 x pi x radius
where pi = 3.14

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[ Analyze the Problem – Question#6 ]

Problem Analysis:
Input:
Process:
Output:

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[ Analyze the Problem – Question#7 ]

Problem Statement 7:

Calculate and display the area of shaded
region in the diagram below.

A
B

C

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[ Analyze the Problem – Question#7 ]

Problem Analysis:
Input:
Process:
Output:

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[ Analyze the Problem – Question#8 ]

Problem Statement 8:

Calculate and display the overtime pay
received by an employee. Overtime rate is
RM500 per hour.

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[ Analyze the Problem – Question#8 ]

Problem Analysis:
Input:
Process:
Output:

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[ Analyze the Problem – Question#9 ]

Problem Statement 9:
Convert the temperature in Fahrenheit (F)
to Celsius (C) using the formula:

C  5 (F  32)
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[ Analyze the Problem – Question#9 ]

Problem Analysis:
Input:
Process:
Output:

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[ Analyze the Problem – Question#10 ]

Problem Statement 10:
Calculate the salary of an employee
who works by hourly basis.
The formula to be used is

Salary = Hours worked * Pay rate

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[ Analyze the Problem – Question#10 ]

Problem Analysis:
Input:
Process:
Output:

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1. Five (5) steps in problem solving.
- Problem Analysis
- Design a Solution
- Implementation
- Testing
- Documentation

2. Identify input, process and output from
a given problem (sequence).

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