Animus Introduction

Animus is an AI programming contest I organized during Exodia 2012, along the lines of the Google AI challenge. This post will get you started with the contest Animus. The goal is to write a bot that will play the game “Dots and Boxes”.

In this post I will assume that you understand the game. If you don’t, please read this page and come back.

Technical Details

From here on, the term “size of the board” will always mean the number of dots along each edge, not the number of boxes. The game board will always be a square.

Each dot is assigned a single number. The top-left dot is assigned 1, and the number is incremented by one as we move to the right (like the periodic table).

The image below shows a 4×4 board, along with the labels assigned to points.

Your submission must include a function move which accepts a single parameter board. board is an object that contains 3 members: size is a single integer that denotes the size of the board, connections is an array that consists of moves that have been performed so far (this is described below), and valid_moves is an array of moves that your bot can legally perform at this point.

Your function must return a single “move”, which is basically an array of two integers which correspond to the dots you wish to connect. For example, [1, 2] will connect the top left dot and the one immediately to its right. board['valid_moves'] and board['connections'] are arrays of moves of this sort.

Here are two sample bots: one which will perform the first valid move it is provided, and another which will perform a random move.

function random_element(myArray) {  
  return myArray[Math.floor(Math.random() * myArray.length)];
}

function move(board) {  
  return random_element(board.valid_moves);
}
function move(board) {  
  return board['valid_moves'][0];
}

Local Development

This package will allow you to test variations of your bot locally. The tool requires that Java is installed on your computer. It has been tested on OS X (Lion), Linux (Ubuntu and Arch) and Windows (Vista). It should be able to work on any other platform as well, if you are having trouble please leave a comment below.

The package contains a JAR file and a directory. The JAR file should be run using the command:

java -Djruby.compat.version=1.9 -jar local_tournament.jar [size]

You should replace [size] with the size of the map you wish to use. You should probably run it using a size of 10, because that is the map size the tournament will be using. Do not omit the argument, doing so will result in the map size being set to 0, which is quite useless.

Results

Name Score
egreavette18
a_iitmandi17
ignite16
rohanag16
abracadabra8
animator8
aounon8
saikiran8
saint3k8
shalmezad8
shapeshifter8
vesper_sword8
1234
maggot0924
randombot4
rohitgupta_hpf4
sukrit3
chamun2
gopi2
shubham9292

Replays from the tournament can be downloaded from here or here. Note that the replays might not work display directly in the newest browsers, you will need to replace history with history_ first.