TIC-TAC-TOE

Requirements

Using the discipline of TDD, build a game of tic tac toe.

The game should allow a human to play against an AI. The AI should be unbeatable. The game should have a user interface of some kind. Rules

The game is played on a 3x3 grid.

You are X, your opponent is O. Players take turns putting their marks in empty squares.

The first player to get 3 of their marks in a row (up, down, across, or diagonally) is the winner.

If all 9 squares are full and no player has 3 marks in a row, the game is over.

Goals

• Create basic/terminal version first
• Would like a visual representation of the game that is not just in the terminal

Ideas for grid data structure:

• Cell as a class
• [["x", "o", ""], ["x", "o", ""], ["x", "o", ""]].flatten
• [{1a: "x"},{1b: "o"},{1c: "o"},2a,2b,2c,3a,3b,3c]

#Psuedo code 1_|| 2_|| 3 | | a b c

[a1,a2,a3,b1,b2,b]

Notes on possible methods:

• update_grid(coordinates) (starting player is always x)

• calculate_score([x,x,x],[o,x,""],["","",""]) => "Player 1 wins"

• place_an_x_within_the_grid # updates the grid

• check_win_condition # After every turn taken by human or computer

• place_an_O_within_the_grid # updates the grid

• check_win_condition(grid) # After every turn taken by human or computer

update_grid(player, position) if player = 1 place_an_x_within_the_grid(position) else place_an_O_within_the_grid end

Flow of program:

• display empty grid

• player enters co-ordinate and hits enter

• displaying an x in that grid

• checking for win state -break on win/drawstate

• arbitary UX pause

• code calculates optimum O position

• code updates grid to include 0

• displaying a 0 in that grid

• checking for win state -break on win/drawstate

• reopen terminal/UI for player

• consider whether the :x/:o element of the win condition can be refactored further to include all 3 winning line position (i.e. full row, full column, diagonal)

• Plan to contain everything within a class so that we have access to instance variables for things like turn

Flow of possible win-states

• neither win/draw
• win conditions are possible
• win conditions are possible && draw conditions are possible
• only draw conditions are possible
• full grid game is a draw

Showing the grid with cell references:

1|2|3 4|5|6 7|8|9