Computer Science Writing Tic Tac Toe

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Computer Science Writing Tic Tac Toe

• H. James de St. Germain
• University of Utah

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GUI vs. Game

• Repeat after me
• The GUI is not the Game
• The GUI is not the Game
• The STATE of the game is enough information to
  rebuild the game knowing nothing else.
• It is easy to go from STATE?GUI.
• It is very hard to go from GUI?STATE

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State ? GUI

• State
• Dog
• Height 2 ft
• Weight 20 pds
• Color aqua
• Type Chow

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GUI ? State

• State????
• What is it? How big? Color? Type?

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Tic Tac Toe

• Lets conceive of all the information and rules to
  tell someone else how to play
• Tic Tac Toe

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Assumptions

• We have a function which will draw the game on
  the computer screen.

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OBJECT

• An object in Programming is a container of
  information.
• class TicTacToe // is how it begins
• What information is necessary to tell someone
  else the STATE of a game?

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Example Pseudo Object

• class Student
• Name
• Age
• Uid
• GPA
• etc

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Class TicTacToe

• Fill in the class member variables here
• But WAIT!
• Member variables can only contain a few types
  of information

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Data Types

• Numbers
• Characters
• Booleans
• Arrays (or Lists of information)
• Objects (combinations of the above)

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Class TicTacToe

• Fill in the class member variables here
• class TicTacToe

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Computer as Scratch Paper

• whos_turn

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Actions (Algorithm)

• We will now work on a recipe that someone could
  follow to play TicTacToe.
• Remember, all references to the STATE of the game
  must refer to our member variables on the
  previous slide.

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TicTacToe Algorithm
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Recap

• All instructions in an algorithm must refer to
  the DATA stored in variables
• All variables have a specific DATA TYPE limiting
  what they can store
• A computers memory is like a piece of paper with
  little boxes on it.

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Final Thought

• When writing a computer program, you should be
  able to write down a list of instructions that
  your friend can follow without you to explain
  anything

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Questions

• Discussion!

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• Fin