FourInARow: Using the GameplayKit Minmax Strategist for Opponent AI

This sample demonstrates how to use the GKMinmaxStrategist class to implement a computer-controlled opponent for turn-based, adversarial games. As part of this demonstration, the sample shows how to structure gameplay model code for use with the minmax strategist using the GKGameModel protocol and related APIs.

Playing the Game

Tap in a column to drop a chip of your color there. (Red moves first, Black moves second.) Get four chips in a row -- horizontally, vertically, or diagonally -- to win.

Building a Game Model

This project builds a game in stages:

1. The AAPLBoard and AAPLPlayer classes implement a generic model for a Four-In-A-Row game. Use the FourInARowTests unit test case to exercise the generic game model.
2. The AAPLViewController class adds a UI for playing the game on an iOS device. With the USE_AI_PLAYER macro left undefined, the game is for two human players.
3. The classes and categories in AAPLMinmaxStrategy.h and AAPLMinmaxStrategy.m extend the generic game model to support using GameplayKit for opponent AI.
4. With the USE_AI_PLAYER macro defined, the AAPLViewController class replaces user control for the second player (black chips) with an AI opponent using the GKMinmaxStrategist class.

For a more thorough discussion of this project, see the chapter "The Minmax Strategist" in GameplayKit Programming Guide.

Requirements

Build

Xcode 7.0, iOS 9.0

Runtime

iOS 9.0

Copyright (C) 2015 Apple Inc. All rights reserved.