Queen B

Strategy

General Flow:

• gather data and setup board by freeing up spaces and finding 'bad_positions' we don't want to move in to (using floodfills and other logic)
• determine if we are boxed in
• determine if we have the opportunity to kill a snake (head to head and tunnel closing)
• determine which food (if any) we want to get
• do the following in order (skip a step if we have determined we don't want to do it or found a move in a previous step)
  • attacking logic (unless we really need to prioritize food)
  • boxed in logic (find exit then determine longest path)
  • food pathing logic (bfs to pre determined food)
  • find 'safe_spots' on the board by rating cells and path to the one that has the best rating/best path
• if for some reason we still don't have a move (caught an error or all moves are fairly bad) do a series of floodfills to determine our best option

This snake is a 'local search' snake that considers a large amount of situations (no predictions on what other snakes are going to do). During development we opted to use a variety of configuration variables so that we could easily modify it to face different bountysnakes. To help make sure this type of approach would work we created a set of static tests and dockerized several 'test' snakes. These helped a lot to ensure that future changes did not break the existing code. Linting was also run periodically.

For the day of the competition this was deployed to a t2 instance in AWS. Seeing as we don't do any look ahead we didn't need a large instance and we were responding within ~50ms on average.

Strategy Brainstorming has some strategies that were discussed (most are not listed).

Requirements

• docker and optionally docker-compose

• or -

• a working Python 3 development environment (getting started guide)
• pip to install Python dependencies

Running

You can run this with docker or locally on your computer.

Docker

docker-compose build
docker-compose up

Dev Helpers

A Makefile is provided to ease tasks. Set up the virtualenv first.

# install dependencies
make bootstrap

# run static tests
make test-static

# clean, lint, test
make test

Local

A virtualenv is suggested when installing python requirements, although it's not required.

python3 -m venv .venv
. .venv/bin/activate

Install dependencies using pip:

$ pip install -r requirements.txt

Then either run the app directly

$ python app.py # supply PORT to override default

Or using uwsgi

$ uwsgi --ini uwsgi/battlesnake-dev.ini # adjust uwsgi params accordingly

Linting

From the top-level directory run the following

flake8 --config setup.cfg

Static Tests

From the /tests/static directory run the following. Currently tests a snake that is running at a specified url in utils.py's TEST_INSTANCE.

python test.py