structured problem solving an introduction

www.hope.ac.uk Faculty of Sciences and Social Sciences

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PEStructured Problem SolvingAn Introduction

Stewart [email protected] 291 3113


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PEAims of the presentation• to quickly list the skills to be developed on

the SPS strand of the course• to officially start the course


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Skills to be developed in the SPS strand of the course

• Problem Solving Skills • Programming Skills• Team Interaction Skills• Presentation Skills• Reflective Skills

The most important bit


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Skills to be developed in the SPS strand of the module



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Problem Solving Skills

• Analysis of Problems– Crossing a busy road– Eating a Pie– Cooking a Pie– Climbing Mount Everest ??????– Getting PieEater to do something complicated– Writing other software to do something

complicated


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• Analysis of the Structure of Solutions– Sequence– Selection– Repetition


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• Structured English– Sequence– Selection– Repetition


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Programming Skills

• Introduction to Java – Java Programming Constructs– Java Trainer– The PieEater

• Java revisited– Object Oriented Concepts– BlueJ Integrated Development Environment

• (http://www.bluej.org/about/what.html)

– The PieEater again plus Close Friends– Graphics and Animation

http://www.bluej.org/about/what.html


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Programming Skills

• Data Structures– Selection of Appropriate Data Structures– Sorting– Searching


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Team Interaction Skills

• Animation Problems– Solved in Groups– Coded in Groups– Tested in Groups


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Presentation Skills

• Presentation of Working Animations– Demonstration of the Running Animation– Explanation of the Choice of Variables– Explanation of the Algorithmic Design– Explanation of the Data Structures Selected– Discussion of Possible Enhancements


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Reflective Skills

• Reflect on Team Work Activities• Reflect on the Scope of the Task• Highlight Possible Failings in the Mechanics

of the Team Work Activity• Suggest Possible Improvements to Team

Work Interaction


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Let the course begin …..


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Your First Seminar

createpieeater();pendown();walk();penup();walk();pendown();turnright();walk();walk();


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Let’s Loop-the-Loop

createpieeater();while (test)

{ actions;}

other actions;

Sequences of Actions each Ending with a Semi Colon

No Semi Colons


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Semi-colons: a working rule

• Do not put them at the end ofwhile()if (){}

• Do put them at the end of other linesint a;a = 7;turnleft();


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while (test) { }

test– clearahead– direction != “SW”– pieinsight

clearahead and pieinsight are either true or falsedirection != “SE” can be evaluated to either true

or false


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Loop Operation

while (test) { actions; }

other actions;Evaluate test

true false


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Test is True

while (test) {» actions;

}other actions;

Enter Body of LoopExecute [actions;]Evaluate test Again

Body of Loop


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Test is True


}other actions;



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Test is True


}other actions;



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You Get the Idea


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Test is False


}other actions;

Jump to other actions; and Continue with the Rest of the Program


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{actions;}

walk();pendown();penup();turnleft();turnright();• You add the rest


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Selection

• The if statement allows us to specify alternative actions depending upon a test


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if (test) { }else { }

if (pieinsight) { eatpie(); }else { walk(); }

Selection


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if inside a loop createpieeater();

randompies(20);while (clearahead) { if (pieinsight) { eatpie(); } else { walk(); } }


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Counting loops - for

int i;createpieeater();for (i=0; i<5; i++) { walk(); }


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In Conclusion

• Problem Solving is a Skill– Riding a Bicycle– Swimming– Keeping Awake in Lectures

• It Cannot be Learned Quickly• It Cannot be Learned without Practice• Every Failure is Part of the Learning Process


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PELecture Exercise 1• Draw the following grid


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PETrace out the following program

createpieeater();turnright();pendown();while (clearahead){walk();}


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PELecture Exercise 1 Answer


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PELecture Exercise 2• Write the program for


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PELecture Exercise 2 Answer

createpieeater();int i;for (i=1 ; i<=4 ; i++)

{ while (clearahead)

{ walk(); }

turnright(); turnright(); }


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PELecture Exercise 3 – spot the syntax error

createpieeater();int i;for (i=1 , i<=4 , i++)

{ while (clearahead)

{ walk() }

turnright(); turnright();


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In Conclusion

• Programming Languages are Merciless– Syntax Matters– Semi Colons can be Dangerous

– In Conclusion: }


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Questions?

• Next…– Problem Solving in your seminars

• More loops• If statements

– Next lecture on Algorithms– Setting of assessment next week

structured problem solving an introduction

Documents

faculty of sciences

social sciences hope45problem

social sciences hope67problem

social sciences hope56problem

social sciences hope11aims

social sciences hope3skills

social sciences hope34skills

social sciences hope78skills