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Introduction to Programming

Concepts & Logic

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- Programs are simply solutions to problems.

- To create a program we have to learn how to think in a different way, the way computers think.

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Chapter 1

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General Problem-Solving

Concepts

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1. Identify the problem

◦ What is the specific problem?

(This means you should determine what is that

you want to change).

◦ Clearly define the goal that you want to

achieve. (What are you trying to achieve?).

◦ Determine what are the inputs and

outputs.

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2. Understand the problem

◦ Gathering data relative to the problems which

your solution can be achieved.

◦ Do not automatically discard any information.

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3. List possible solutions to the problem

◦ Generate as many potential solutions as

possible.

◦ List the features for each possible solution.

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4. Select the best way to solve the problem

from the list of alternative solutions.

◦ Establish criteria to help when choosing the

solution

◦ Select the best solution.

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5. List instructions that enable you to solve

the problem using the selected solution

(Do Stage).

◦ Planning:

Create a numbered, step-by-step set of

instructions

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6. Evaluate the solution(Review and Revise)..

◦ Test the solution

Are the results accurate?

Does the solution solve the original problem?

Does it satisfy the needs of the user?

Is it acceptable to the user?

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Now let’s put problem-solving into

action!

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Problem description Steps Outcome. Eman is a doctor and she isn’t in regular contact with her old friends. She is getting caught up in the demands of work and family and she’s not setting aside time specifically for old friends.

Identify the problem. Problem: wanting to get contact to the old friends. Goal: get contact to the old friends.

Understand the problem. Facts: Searching for e-mail, telephone, home address…etc.

list possible solutions to the problem

1. Schedule a time e.g. every Sat. to contact by writing emails letters. (Cheap - long time to write a letter – no need to be at the same time available).

2. Buy plan tickets to visit them. (real contacts, costly, must have free time to do it) 1. Using phone call to contact.(real contact,

acceptable costs, need short free time ). Select the best solutions to

the problem. Criteria: 1- Time. 2-Cost. 3- Interactivity. So, phoning would be the best.

List instructions (Do Stage) Start calling tomorrow at launch time. Schedule every Sunday at 10 am for calling Write notes to remember on mirror and… Tell the friend in advance to be ready.

Evaluate the solution (Review and Revise).

Had great conversation but set a timer when she’s talking so that she will not spend more on the phone bill.

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Problem

description

Steps Outcome.

Today is the final

day for Abeer in

high school, she &

her family

gathered to decide

which university

for here to attend.

Identify the problem. Problem: Enrolling in a university & department

Goal: Name university and department that she will

this year.

Understand the problem. Facts:

Searching for Universities available.

Knowing her grades, hobbies, specialties

and Gender.

list possible solutions to the

problem

go local university.(speed, not have desired

section, monthly reward)

go a broad.(trip expenses, have desired section,

free enrolment, monthly reward)

go private university.( trip expenses very

expensive , school I prefer, enrolment is not free )

Select the best solutions to

the problem.

Criteria:

1- enters high ranked university and

desired section.

2- Not expensive.

3- Free.

So, solution 2.

List instructions (Do Stage) 1. Send an enrol application to the university.

2. Wait for reply.

3. Pack your stuff, go to university.

4. Attend first day.

Evaluate the solution

(Review and Revise).

I felt lonely, grades were low.

So, must change solution(revaluate)

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Algorithmic Solutions Steps involved in following a set of instructions. The solution will be the same each time the algorithm is

followed. Most computers use algorithmic types of problems.

Heuristic Solutions Solutions that can’t be reached by following a direct set of

steps. Created based on knowledge and experience…and by trial and

error.

The results may not produce the same results each time the algorithm is executed.

Artificial intelligence deals with heuristic types of problems.

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The instructions that will result in the best

solution.

The result may be:

More Efficient

Faster

More Understandable

More Maintainable

Reusable

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The outcome of the program

May take any form:

Printout

Updated files

Output to monitor, speakers, etc.

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The set of instructions that make up the

solution after they have been coded into a

particular computer language.

Although we won’t be actually writing programs, at least not in any

specific language, this is what we will be working toward throughout

this course!

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summary

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There are 6 steps in problem solving

There are two types of problem solutions :

algorithmic and heuristic.

Algorithmic solutions reached step by step

Heuristic solutions through trial and error