Ants Tutorial

The strategies implemented in the starter packages are only meant to serve as a starting point for making your bot. In fact, it's almost the worst strategy to use. The starter packages also come with some useful functions to help you develop a smarter strategy. This page will walk you through a series of improvements. With each step that you complete, your bot will get smarter and you should notice your ranking start to rise.

Prerequisites

For this tutorial, we will be using the Python starter package. In order to use python, you must have a python interpreter downloaded and installed on your machine. See Getting Started with Python.

Note: The tools come with the game engine written in python. You will need to install a python interpreter to run the game engine regardless of which language you are programming in.

You'll also want to download the tools and install them on your machine.

Setting Up

Create a folder to put both the tools and the starter bot and unzip both files in that location. You should have something that looks like this:

C:\aichallenge>tree
Folder PATH listing
C:.
+----tools
    +---mapgen
    +---maps
    |   +---example
    |   +---maze
    |   +---multi_hill_maze
    |   +---symmetric_random_walk
    +---sample_bots
    |   +---csharp
    |   +---java
    |   +---php
    |   |   +---tests
    |   +---python
    +---submission_test
    +---visualizer
        +---data
        |   +---img
        +---js

C:\aichallenge>dir /b
ants.py
MyBot.py
tools

C:\aichallenge>dir /b
AbstractSystemInputParser.java
AbstractSystemInputReader.java
Aim.java
Ants.java
Bot.java
Ilk.java
make.cmd
Makefile
Manifest.txt
MyBot.java
Order.java
Tile.java
tools

Testing

Now lets make sure everything is working by running a test game. The tools comes with a utility called "playgame.py" that will help up test our bot. It also comes with an example script called "play_one_game.cmd" to show you how to use it.

C:\aichallenge>tools\play_one_game.cmd
running for 500 turns
                     ant_count    c_turns    climb?    cutoff food r_turn ranking_bots   s_alive      s_hills       score     w_turn winning
turn    0 stats:  [1,1,1,1,0]    0    [1,1,1,1]   -     20    0        None     [1,1,1,1] [1,1,1,1] [1,1,1,1]   0     None
turn    1 stats:  [1,1,1,1,0]    0    [1,1,1,1]   -     20    1     [0,0,0,0]   [1,1,1,1] [1,1,1,1] [1,1,1,1]   1    [0,1,2,3]
turn    2 stats:  [1,1,1,1,0]    0    [1,1,1,1]   -     24    1     [0,0,0,0]   [1,1,1,1] [1,1,1,1] [1,1,1,1]   1    [0,1,2,3]
turn    3 stats:  [1,1,1,1,0]    0    [1,1,1,1]   -     24    1     [0,0,0,0]   [1,1,1,1] [1,1,1,1] [1,1,1,1]   1    [0,1,2,3]
turn    4 stats:  [1,1,1,1,0]    0    [1,1,1,1]   -     22    1     [0,0,0,0]   [1,1,1,1] [1,1,1,1] [1,1,1,1]   1    [0,1,2,3]
turn    5 stats:  [2,1,2,1,0]    0    [1,1,1,1]   -     22    1     [0,0,0,0]   [1,1,1,1] [1,1,1,1] [1,1,1,1]   1    [0,1,2,3]
...

If you saw the preceding output, then everything should be working.

Create Test Script

Now, let's create our own script for this tutorial that uses a new map and our own bot.

C:\aichallenge>notepad tutorial.cmd

user@localhost:~$ gedit tutorial.sh

user@localhost:~$ chmod u+x tutorial.sh

The contents of the text file will be:

python tools/playgame.py "python MyBot.py" "python tools/sample_bots/python/HunterBot.py" --map_file tools/maps/example/tutorial1.map --log_dir game_logs --turns 60 --scenario --food none --player_seed 7 --verbose -e

python tools/playgame.py "java -jar MyBot.jar" "python tools/sample_bots/python/HunterBot.py" --map_file tools/maps/example/tutorial1.map --log_dir game_logs --turns 60 --scenario --food none --player_seed 7 --verbose -e

make

• The first 2 options are the names of the bots to run. We'll be using HunterBot as our opponent.
• The --map_file options specifies the map to use. This is a simple map with 2 ant hills.
• The --log_dir options specifies a location to store the replay file, and optionally the logs of bot input and output and errors.
• The --turns options specifies when to stop the game if it goes too long. We don't want a lot of extra output, so will keep it to 60 turns.
• The --scenario option allows us to use the food specified on the map as the starting food. It has been specially placed for this tutorial. (remove this for real games)
• The --food none option allows us to turn off the food spawning during the game. Again, it will be off just for this tutorial. (remove this for real games)
• The --player_seed option ensures that you can get the same game results as in the tutorial. HunterBot will use this value to initialize the random number generator, so it will always do the same thing. (Note: if you want your bot to be able to replay games for debugging, you'll want to implement this as well.)
• The --verbose option will print a running total of game stats so we can watch the progress as the game is played.
• The -e option will output any bot errors to the console, so if you make a mistake during the tutorial you can see what the error message is. (Note: remove the --scenario and --food none options when you want to play games on different maps.) (Note: the tutorial was made with view radius 55, which is not the official view radius. You can add --viewradius 55 to the engine to override the default and make the tutorial bot behave the same as the same replays.) (Both HunterBot and the tutorial bot we will be making are deterministic, meaning if you give them the same input, they will produce the same set of moves. This means if you follow along exactly, you should see the tutorial games play out exactly the same on your machine. The python code that sorts lists will sort every element, the java code wasn't implemented to sort correctly, so results may differ.)

Let's run the command and see how the starter bot does.

C:\aichallenge>tutorial

user@localhost:~$ ./tutorial.sh

You should see the following output:

    running for 60 turns
                      ant_count c_turns climb? cutoff food r_turn ranking_bots s_alive s_hills score  w_turn winning
    turn    0 stats:   [1,1,0]     0    [1,1]    -     18    0        None      [1,1]   [1,1]  [1,1]   0     None
    turn    1 stats:   [1,1,0]     0    [1,1]    -     16    1       [0,0]      [1,1]   [1,1]  [1,1]   1     [0,1]
    turn    2 stats:   [2,1,0]     0    [1,1]    -     16    1       [0,0]      [1,1]   [1,1]  [1,1]   1     [0,1]
    turn    3 stats:   [2,2,0]     0    [1,1]    -     15    1       [0,0]      [1,1]   [1,1]  [1,1]   1     [0,1]
    turn    4 stats:   [2,3,0]     0    [1,1]    -     14    1       [0,0]      [1,1]   [1,1]  [1,1]   1     [0,1]
    turn    5 stats:   [2,4,0]     0    [1,1]    -     14    1       [0,0]      [1,1]   [1,1]  [1,1]   1     [0,1]
    turn    6 stats:   [2,4,0]     0    [1,1]    -     14    1       [0,0]      [1,1]   [1,1]  [1,1]   1     [0,1]
    turn    7 stats:   [2,4,0]     0    [1,1]    -     14    1       [0,0]      [1,1]   [1,1]  [1,1]   1     [0,1]
    turn    8 bot 0 eliminated
    turn    8 stats:   [0,4,0]     0    [0,1]    -     14    1       [0,0]      [0,1]   [1,1]  [1,1]   1     [0,1]
    score 1 3
    status eliminated survived
    playerturns 8 8

The game only ran for 8 turns, which is very fast. It looks like player 0 (that's us) got eliminated. A browser should have launched to show you the game in the visualizer.

# [ { "embedded": true }, 600, 600, { "speedFactor": 0, "speedFastest": 2, "speedSlowest": 2, "zoom": 1 }, "example_games/tutorial.0.replay" ]

You can see the starter bot's strategy is so horrible, it kills itself by colliding 2 ants. That will be our first improvement.

Next

Here's the list of improvements we'll be implementing in this tutorial:

1. Step 1: Avoiding Collisions
2. Step 2: Gathering Food
3. Step 3: Not Blocking Hills
4. Step 4: Explore the Map
5. Step 5: Attack the Enemy Hills