This is a tic-tac-toe with a command line interface that lets you play a tic-tac-toe with the computer.

The implementation is done in Ruby using the min-max algorithm.

• Install Ruby (Ex: In Mac, brew install ruby)
• Clone the project

git clone https://github.com/afsalthaj/tic-tac-toe

• Play game

cd tic-tac-toe
cd ui
ruby command_line_game.rb

• Computer plays all the future games the moment you start the game.
• Computer ranks all the moves, and depending the player, it choose the move with either the maximum score, or minimum score. Maximum score if next move is "Computer's" else minimum.
• The computer player is hard-coded as :X and the user is identified as :O

• Minimax algorithm, from a high level perspective, is fairly intuitive
• It is always interesting to build a recursive algorithm.
• Less code.

• Relatively a complex recursion once developed.
• First stage computations taking time. Depth factor can be incorporated.

Game Runner is sort of a client of Tic tac toe Game that makes use of the strategy and the game. Game class is responsible for keeping track of the state of the game. Obviously state of the game is represented by the player, the board and the complete set of moves available at a point in time.

• All that I did here is, simulating a game in test case, and asserting each moves/possible moves.
• Asserting each move/possible move is done intuitively and did't focus much on min-max algorithm.
• File "game.rb" and "game_runner.rb" are the ones tested. File "play.rb" is just invoking the game.

Run tests by:

// In the root directory

// Optional command
brew install ruby
bundle install

//run tests
ruby spec.rb

// get the coverage report
cd coverage
open index.html

• It seems the algorithm selected is quite advanced, and is not scalable.
• The first iteration of every game starts in 20 seconds, which is not so good.
• The first selection of player carried over to the rest of the games. This is to be made flexible
• Mock command line input output testing rspec

• https://www.quora.com/Is-there-a-simple-explanation-of-a-minimax-algorithm
• https://www.youtube.com/watch?v=zDskcx8FStA
• https://en.wikipedia.org/wiki/Minimax