Octopus Farmer 🐙🌱

This is a little text-based game in which you play as an octopus that attempts to catch fish with its tentacles. Each fish consumed gives you a certain number of points, and your goal is to maximize the number of points you get within a certain number of time steps, by writing the best code you can to optimize the octopus's movement.

Installation

$ npm install && npm run build

Running the program

$ node ./dist/octofarm.js

There are two ways to run the game.

• node ./dist/octofarm.js run will run the game with a live, text-based display showing the octopus, fish, and current score. You can control the octopus with the arrow keys.
• node ./dist/octofarm.js farm will run the game in a headless mode, only showing the summary statistics. This is much faster and good for testing your octopus logic over a long run.

Your job: Writing the MyOctopus class

The file src/octopus.ts has the code for the Octopus class, which is the base class for octopuses. Your job is to write a subclass of Octopus called MyOctopus that implements the move method. The move method is called once per time step, and should move the octopus in a way that maximizes the number of points it gets.

The default implementation of MyOctopus is to move randomly, which is not very effective.

The Octopus can move up to this.speed units each time step. The Octopus has a total of this.num_tentacles tentacles, and each tentacle can reach a fish up to this.reach units away. As the Octopus moves, the game will automatically cause the Octopus to grab the nearest fish (within this.reach units away) with one of its free tentacles. Each time step that a fish is grabbed by a tentacle, the fish loses this.attack_power health. If the fish's health drops to 0, the fish is eaten and the Octopus gets fish.value points added to its score. (All of the above logic is automated by the game; you don't have to implement this!)

Note that fish themselves move and some of them tend to move away from the Octopus when grabbed by a tentacle. If a fish moves beyond this.reach units, the Octopus will automatically drop the fish, and the fish will automatically be restored to full health! Given that it may take several time units of grabbing onto a fish with a tentacle to kill it, you may want to consider having your octopus move closer to fish it has already grabbed, lest it lose the points for fish that try to swim away.

Moving the Octopus

The Octopus can use the following methods to help it move:

• this.x and this.y are the octopus's current coordinates.
• this.moveTo(x, y) will move the octopus to the given coordinates, as long as those coordinates are within this.speed units of the octopus's current position. (If you attempt to move too far, the octopus will not move at all.)
• this.moveLeft(), this.moveRight(), this.moveUp(), and this.moveDown() will move the octopus this.speed units in the given direction.
• this.distance(x, y) returns the distance between the octopus's current position and the given coordinates.

Eating fish

The Octopus will want to observe the state of the fish in the world and try to maximize its points by moving towards the tastiest fish. You can use the following methods to help:

• this.world.getFish() returns an array of all the fish in the world. Each fish is an instance of the Fish class, as described below.
• this.tentacles is an array containing each of the fish that the octopus is currently grabbing with its tentacles. There can be no more than this.num_tentacles fish in this array. You are not to modify this array -- it is there to help you decide how to move the octopus.

Note that your job is not to modify the behavior of the Octopus apart from its movement. That is, the Octopus's eating and tentacle-grabbing behavior is fixed and you should not attempt to change that; all you are trying to do is move the Octopus in the optimal fashion to maximize your score.

The Fish class

The Fish class represents a fish to eat, and has the following properties. You are not to modify any of these properties in your code, but you are free to read them.

• fish.x and fish.y are the fish's current coordinates.
• fish.value is the number of points the fish is worth, if consumed.
• fish.health is the fish's current health. If this reaches 0, the fish is eaten and the octopus gets fish.value points added to its score.
• fish.speed is the fish's speed. Each time step, the fish will move up to fish.speed units.
• fish.fright is the probability that a fish will try to swim away from the octopus on any time step that it is being grabbed by a tentacle. As you might imagine, the tastiest and highest-value fish tend to be the most skittish and will swim away more often!

Scoring

Your score is based on the number of points you get by running the game for 1, 000, 000 steps. You can run: node ./dist/octofarm.js farm which will run the game and show you the final score. The default random-walk implementation of MyOctopus gets a score of around 1000 points, so we're hoping you can do significantly better than that by being smart about moving the octopus!

Good luck!