Package ai.nettogrof.battlesnake.snakes

Class AbstractTreeSearchSnakeAI

java.lang.Object

ai.nettogrof.battlesnake.snakes.AbstractSnakeAI

ai.nettogrof.battlesnake.snakes.AbstractSearchSnakeAI

ai.nettogrof.battlesnake.snakes.AbstractTreeSearchSnakeAI

Direct Known Subclasses:

AbstractMultiThreadSnakeAI

public abstract class AbstractTreeSearchSnakeAI
extends AbstractSearchSnakeAI

Any snake using a tree-search could extend this abstract class it contains basic constant fields, related to the field name in json call from BattleSnake. Also some method that any snake must implements.

Version:

Spring 2022

Author:

carl.lajeunesse

Field Summary

Fields

Modifier and Type	Field	Description
protected AbstractNode	lastRoot	Keep the root node from the previous move, to be able to continue search from the previous "tree"
protected static String	NODECOUNT	Constant Field name
protected Constructor<? extends AbstractSearch>	searchType	What kind of search that gonna be use

Fields inherited from class ai.nettogrof.battlesnake.snakes.AbstractSearchSnakeAI

losing, minusbuffer, nodeTotalCount, timeout, timeTotal, winning

Fields inherited from class ai.nettogrof.battlesnake.snakes.AbstractSnakeAI

apiversion, BOARD, BODY, DOWN, fileConfig, FOUR_SNAKE, gameId, HEAD, HEALTH, height, HEIGHT_FIELD, LEFT, log, MOVESTR, NAME, RIGHT, rules, SHOUT, SINGLE_SNAKE, SNAKES, SQUAD, TURN, TWO_SNAKE, UPWARD, width, WIDTH_FIELD, YOU

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	AbstractTreeSearchSnakeAI()	Basic and unsed constructor
protected	AbstractTreeSearchSnakeAI(String gameId)	Constructor with the gameid,

Method Summary

Modifier and Type	Method	Description
protected AbstractNode	chooseBestMove(AbstractNode root)	Choose the best move, based on the assumption that the opponent will always choose the best counter.
private void	fillList(gnu.trove.list.array.TFloatArrayList[] upward, gnu.trove.list.array.TFloatArrayList[] down, gnu.trove.list.array.TFloatArrayList[] left, gnu.trove.list.array.TFloatArrayList[] right, AbstractNode node)	This method fill 4 list (one for each direction ) with the score of each node based on the move direction
protected AbstractNode	findChildNewRoot(List<SnakeInfo> snakes, FoodInfo food, HazardSquare hazard)	Check in the previous search if a child from root, is equals the current board situation.,
protected AbstractNode	finishHim(AbstractNode root, AbstractNode winner)	In a winning position, this method try to find the shortest way to win.
protected abstract AbstractNode	genRoot(com.fasterxml.jackson.databind.JsonNode moveRequest)	Generate the root node based on the /move request
private int	getMaxDepth(AbstractNode root)	Check the depth of the biggest branch
protected AbstractNode	lastChance(AbstractNode root)	In a losing position, this method try to find the longest way, hpoing that the opponent make a mistake.
private void	logValue(gnu.trove.list.array.TFloatArrayList[] upward, gnu.trove.list.array.TFloatArrayList[] down, gnu.trove.list.array.TFloatArrayList[] left, gnu.trove.list.array.TFloatArrayList[] right)	Log value for each possible move, that help to debug/understand why the snake choose which move.
Map<String,String>	move(com.fasterxml.jackson.databind.JsonNode moveRequest)	This method will be call on each move request receive by BattleSnake
void	setTimeout(int timeout)	Set the move timeout
void	singleThreadTreeSearch(AbstractNode root, Long startTime, GameRuleset rules)	Execute the single Thread tree search
protected void	treeSearch(AbstractNode root, Long startTime, GameRuleset rules)	Execute the tree search

Methods inherited from class ai.nettogrof.battlesnake.snakes.AbstractSearchSnakeAI

addNodeTotalCount, addTimeTotal, end, generateResponse, genSearchType, setProperties

Methods inherited from class ai.nettogrof.battlesnake.snakes.AbstractSnakeAI

getFileConfig, getInfo, ping, setFileConfig, start

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

NODECOUNT

protected static final String NODECOUNT

Constant Field name

See Also:

Constant Field Values

lastRoot

protected AbstractNode lastRoot

Keep the root node from the previous move, to be able to continue search from the previous "tree"

searchType

protected Constructor<? extends AbstractSearch> searchType

What kind of search that gonna be use

Constructor Detail

AbstractTreeSearchSnakeAI

protected AbstractTreeSearchSnakeAI()

Basic and unsed constructor

AbstractTreeSearchSnakeAI

protected AbstractTreeSearchSnakeAI(String gameId)

Constructor with the gameid,

Parameters:

gameId - String of the gameid field receive in the start request.

Method Detail

move

public Map<String,String> move(com.fasterxml.jackson.databind.JsonNode moveRequest)

This method will be call on each move request receive by BattleSnake

Specified by:

move in class AbstractSnakeAI

Parameters:

moveRequest - Json call received

Returns:

map of field to be return to battlesnake, example "move" , "up"

getMaxDepth

private int getMaxDepth(AbstractNode root)

Check the depth of the biggest branch

Parameters:

root - Root node

Returns:

depth (int)

treeSearch

protected void treeSearch(AbstractNode root,
                          Long startTime,
                          GameRuleset rules)
                   throws ReflectiveOperationException

Execute the tree search

Parameters:

root - The root node

startTime - The start time in millisecond

rules - Game ruleset

Throws:

ReflectiveOperationException - In case of invalid search type

genRoot

protected abstract AbstractNode genRoot(com.fasterxml.jackson.databind.JsonNode moveRequest)

Generate the root node based on the /move request

Parameters:

moveRequest - Json request

Returns:

AbstractNode the root

finishHim

protected AbstractNode finishHim(AbstractNode root,
                                 AbstractNode winner)

In a winning position, this method try to find the shortest way to win.

Specified by:

finishHim in class AbstractSearchSnakeAI

Parameters:

root - The current Root node

winner - The predetermine best move

Returns:

the best AbstractNode

lastChance

protected AbstractNode lastChance(AbstractNode root)

In a losing position, this method try to find the longest way, hpoing that the opponent make a mistake.

Specified by:

lastChance in class AbstractSearchSnakeAI

Parameters:

root - The current Root node

Returns:

the best AbstractNode

chooseBestMove

protected AbstractNode chooseBestMove(AbstractNode root)

Choose the best move, based on the assumption that the opponent will always choose the best counter.

Parameters:

root - The current Root node

Returns:

the best AbstractNode

fillList

private void fillList(gnu.trove.list.array.TFloatArrayList[] upward,
                      gnu.trove.list.array.TFloatArrayList[] down,
                      gnu.trove.list.array.TFloatArrayList[] left,
                      gnu.trove.list.array.TFloatArrayList[] right,
                      AbstractNode node)

This method fill 4 list (one for each direction ) with the score of each node based on the move direction

Parameters:

upward - float array list

down - float array list

left - float array list

right - float array list

node - parent node

logValue

private void logValue(gnu.trove.list.array.TFloatArrayList[] upward,
                      gnu.trove.list.array.TFloatArrayList[] down,
                      gnu.trove.list.array.TFloatArrayList[] left,
                      gnu.trove.list.array.TFloatArrayList[] right)

Log value for each possible move, that help to debug/understand why the snake choose which move.

Parameters:

upward - float array list

down - float array list

left - float array list

right - float array list

findChildNewRoot

protected AbstractNode findChildNewRoot(List<SnakeInfo> snakes,
                                        FoodInfo food,
                                        HazardSquare hazard)

Check in the previous search if a child from root, is equals the current board situation.,

Parameters:

snakes - List of snakes

food - Food info

hazard - Hazard Info

Returns:

null or child node

setTimeout

public void setTimeout(int timeout)

Set the move timeout

Parameters:

timeout - the timeout to set

singleThreadTreeSearch

public void singleThreadTreeSearch(AbstractNode root,
                                   Long startTime,
                                   GameRuleset rules)
                            throws ReflectiveOperationException

Execute the single Thread tree search

Parameters:

root - The root node

startTime - The start time in millisecond

rules - Game ruleset

Throws:

ReflectiveOperationException - In case of invalid search type