Minimax Algorithm

Tic-Tac-Toe Game

Tic-Tac-Toe is a tic-tac-toe game built on top of Node.js and opponent AI based on minimax algorithm with alpha beta pruning

Heroku deployed Tic-Tac-Toe (Currently on free tier and loading may be delayed): http://www.tictactoealgo.com/

A 4x4 version of the game was also created: http://www.tictactoealgo.com/fourbyfour

To play the game locally:

• This assumes Node and NPM is installed locally on computer
• Download the minimax folder, navigate to minimax folder in terminal, and npm install & npm start server/server.js
• Visit http://localhost:3000/ to play tic-tac-toe locally or http://localhost:3000/fourbyfour

Tic-Tac-Toe API

Players can also interact with the game by making API post requests to the server and the game will return a tic-tac-toe board with the computer's move.

To get started:

• Download the files, navigate to tic-tac-toe folder in terminal, and npm install & start the server
• Play against the computer by sending post requests to http://localhost:3000/api

API Board Format

• An empty Tic-Tac-Toe board is represented as an array with 9 empty strings: ["","","","","","","","",""]
• Top left position of the tic-tac-toe board is represented by position 0 in the array.
• Middle position of the tic-tac-toe board is represented by position 4 in the array.
• Bottom right position of the tic-tac-toe board is represented by position 8 in the array.
• You can visualize the arrays positions as such:

Gameplay

• Player 1 is represented by "X" and Player 2 is represented by "O".
• If an empty array is sent to the server, the computer will be Player 1.
• If an array with a single 'X' and 8 empty strings is sent to the server, the computer will be Player 2.
• The game is designed so the computer never loses a game and will always make the most optimal move.

API Post Request

To play a game, send a JSON post request to http://localhost:3000/api with "board" as the key and the array as the value.

• Example: {"board": ["","","","","","","","",""]}

The server will respond with a JSON board that includes the computers move:

• Example Post Request: {"board": ["X","","","","","","","",""]}
• Subsequent Response: {"board": ["X","","","","O","","","",""]}

Additionally, a post request can be made to http://localhost:3000/api/fourbyfour to play a 4x4 game.