Lecturer : Koo Lee Chun (Ext. 305)

ICT 1101

PROGRAM LOGIC FORMULATION Topic 2 : Problem Solving Organization

Learning Outcome

Successful students should be able to:

• List and describe the basic tools used to aid in the development of

a solution to a problem :

• Problem Analysis Chart (PAC)

• Structure Chart or Interactivity Chart

• IPO Chart

• Algorithms

• Flowcharts

• Describe the categories of documentations

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How computer store data

• Data are stored internally in memory location according to variable

names

• These memory locations are temporary, as internal memory

is volatile.

• When a program is completed or the computer is turned off, the

content in the memory is destroyed.

• Data that needs to be retained or intended for future use should

be stored externally on a storage medium such as hard disk or

floppy disk in storage area called files

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Communication with Computer

• Basically, for a computer to “understand” a message, it

requires instructions with specific rules.

• If the instructions that are provided is incorrect the computer may

give an error message, the wrong answer or may not respond at all.

• The main challenge in problem solving is to provide the most

efficient solution.

• When efficiency is important, only then should each solution be

examined and kept or discarded

• Two programmers may develop equally good solutions to a

problem, but the solutions may look entirely different.

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Organizing the problem

• Some organization tools can be used to help us learn to solve

problem in computer. These included :

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• line the beginning of problem analysis Problem Analysis

Chart (PAC)

• shows the overall solution layout or structure

Structure Chart or Interactivity Chart

• shows the input, processes and output of a solution IPO Chart

• show the sequence of instructions comprising the solution Algorithms

• graphic representations of the algorithms. Flowcharts

Problem Analysis Chart (PAC)

• Divide problem into four major parts.

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PAC Example

Problem : Calculate the gross pay of an employee who worked based

on hourly rate. Formula to be used is GrossPay = Hours x Pay rate

The asterisk (**) in the Solution Alternatives column indicates that this

alternative will be chosen.

PAC helps to identify essential data and information, and disregards

the nonessential

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Structure Chart or Interactive Chart

• Divide the processing into subtasks called modules and connect

them together to show interaction of processing between the

modules

• Each modules contain instructions to accomplish a specific task

such as entering data, printing the result, calculating result

• There will be one module (Control or Main module) that control

the flow to most of the modules

• The Control Module should be placed at the top-most of the chart,

while the subtasks are then located below it

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Structure Chart (Cont..)

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Indicate that the modules are part

of a set of modules that are

processed many times

Indicate only one of the module will

be executed based on the decision

Structure chart Example

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IPO Chart

• IPO (Input-process-output) chart extends and organizes the

information in the problem analysis chart

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Writing Algorithms

• After using the structure chart and the IPO chart, the next step is

develop sets of instruction for computer, called algorithm.

• The programmers writes a separate sets of instructions for each

module in the structure chart

• The algorithms pull the structure chart and IPO chart together to

give a logical step-by-step solution.

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Algorithm Example

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Note: END – end the entire program EXIT – exit point of the module

Flowchart

• Based on algorithms, the programmer produce flowchart, a

graphical representation of the algorithms.

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Flowchart (cont..)

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Example Flowchart

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Example Flowchart (cont..)

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Documentation

• 2 basic types of documentation:

• Internal documentation :

• consists of remarks written with the instructions to

explain what is being done in the program.

• For programmer

• External :

• made up of the manuals or help menus written about

the solution.

• For user of the system

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Review Learning Outcome

Successful students should be able to:

• List and describe the basic tools used to aid in the development of

a solution to a problem :

• Problem Analysis Chart (PAC)

• Structure Chart or Interactivity Chart

• IPO Chart

• Algorithms

• Flowcharts

• Describe the categories of documentations

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Solve a problem

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All marble balls have the same weight (3g) except one

(3.5g).

Can you help to identify this marble ball from others ?