tic-tac-toe-optimal-turn/README.md

Tic-tac-toe optimal turn package based on alpha-beta algorithm.

# Tic-tac-toe optimal turn
## Description
Tic-tac-toe optimal turn package based on alpha-beta algorithm. That package determines the AI's move
and returns next optimal step based on the given board. Only tested on a 3x3, 4x4 board.

## Installation

```
npm install tic-tac-toe-optimal-turn
```

## Usage

```
const optimalMove = getOptimalTurn({ playerSymbol, gameField })  //returns a Number
```

### Parameters

`gameField` presented as an array of `'X'` and `'O'`, empty cell as `null`:
```
const gameField = [ null, 'O', 'X',
                    'X',  'X', 'O',
                    null, 'O', 'O' ] //3x3 game field
```

`playerSymbol` - symbol of the player for whom the next move is calculated:
```
const playerSymbol = 'X' //String
```

`boardSize` - optional, 3 by default. For game fields more than 3x3. 
```
const boardSize = 3 //Number
```

### Example 3x3 game field
```
import { getOptimalTurn } from 'tic-tac-toe-optimal-turn'

const playerSymbol = 'X'
const gameField = [ null, 'O', 'X',
                    'X',  'X', 'O',
                    null, 'O', 'O' ] //3x3 game field
                    
const optimalMove = getOptimalTurn({ playerSymbol, gameField })  //returns 6
```

### Example 4x4 game field
```
import { getOptimalTurn } from 'tic-tac-toe-optimal-turn'

const boardSize = 4
const playerSymbol = 'X'
const gameField = [ null, null, null, null,
                    null, 'O',  null, 'X',
                    null, null, 'O',  null,
                    null, 'X',  'X',  'O' ] //4x4 game field
                    
const optimalMove = getOptimalTurn({ boardSize, playerSymbol, gameField })  //returns 0
```

### TypeScript
```
import { FieldCellType, PlayerSymbolType, getOptimalTurn } from 'tic-tac-toe-optimal-turn'

const playerSymbol: PlayerSymbolType = 'X'
const gameField: FieldCellType = [ null, 'O', 'X',
                                   'X',  'X', 'O',
                                   null, 'O', 'O' ] //3x3 game field
                    
const optimalMove = getOptimalTurn({ playerSymbol, gameField })  //returns 6
```