competition_agent.py

"""Implement your own custom search agent using any combination of techniques
you choose.  This agent will compete against other students (and past
champions) in a tournament.

         COMPLETING AND SUBMITTING A COMPETITION AGENT IS OPTIONAL
"""
import random


class SearchTimeout(Exception):
    """Subclass base exception for code clarity. """
    pass


def custom_score(game, player):
    """Calculate the heuristic value of a game state from the point of view
    of the given player.

    This should be the best heuristic function for your project submission.

    Parameters
    ----------
    game : `isolation.Board`
        An instance of `isolation.Board` encoding the current state of the
        game (e.g., player locations and blocked cells).

    player : object
        A player instance in the current game (i.e., an object corresponding to
        one of the player objects `game.__player_1__` or `game.__player_2__`.)

    Returns
    -------
    float
        The heuristic value of the current game state to the specified player.
    """
    raise NotImplementedError


class CustomPlayer:
    """Game-playing agent to use in the optional player vs player Isolation
    competition.

    You must at least implement the get_move() method and a search function
    to complete this class, but you may use any of the techniques discussed
    in lecture or elsewhere on the web -- opening books, MCTS, etc.

    **************************************************************************
          THIS CLASS IS OPTIONAL -- IT IS ONLY USED IN THE ISOLATION PvP
        COMPETITION.  IT IS NOT REQUIRED FOR THE ISOLATION PROJECT REVIEW.
    **************************************************************************

    Parameters
    ----------
    data : string
        The name of the search method to use in get_move().

    timeout : float (optional)
        Time remaining (in milliseconds) when search is aborted.  Note that
        the PvP competition uses more accurate timers that are not cross-
        platform compatible, so a limit of 1ms (vs 10ms for the other classes)
        is generally sufficient.
    """

    def __init__(self, data=None, timeout=1.):
        self.score = custom_score
        self.time_left = None
        self.TIMER_THRESHOLD = timeout

    def get_move(self, game, time_left):
        """Search for the best move from the available legal moves and return a
        result before the time limit expires.

        **********************************************************************
        NOTE: If time_left < 0 when this function returns, the agent will
              forfeit the game due to timeout. You must return _before_ the
              timer reaches 0.
        **********************************************************************

        Parameters
        ----------
        game : `isolation.Board`
            An instance of `isolation.Board` encoding the current state of the
            game (e.g., player locations and blocked cells).

        time_left : callable
            A function that returns the number of milliseconds left in the
            current turn. Returning with any less than 0 ms remaining forfeits
            the game.

        Returns
        -------
        (int, int)
            Board coordinates corresponding to a legal move; may return
            (-1, -1) if there are no available legal moves.
        """
        # OPTIONAL: Finish this function!
        raise NotImplementedError