hog.py

"""CS 61A Presents The Game of Hog."""

from dice import six_sided, four_sided, make_test_dice
from ucb import main, trace, interact

GOAL_SCORE = 100  # The goal of Hog is to score 100 points.

######################
# Phase 1: Simulator #
######################


def roll_dice(num_rolls, dice=six_sided):
    """Simulate rolling the DICE exactly NUM_ROLLS > 0 times. Return the sum of
    the outcomes unless any of the outcomes is 1. In that case, return 1.

    num_rolls:  The number of dice rolls that will be made.
    dice:       A function that simulates a single dice roll outcome.
    """
    # These assert statements ensure that num_rolls is a positive integer.
    assert type(num_rolls) == int, 'num_rolls must be an integer.'
    assert num_rolls > 0, 'Must roll at least once.'
    # BEGIN PROBLEM 1
    flag = False
    sum = 0
    while num_rolls:
        temp = dice()
        if temp == 1:
            flag = True
        sum += temp
        num_rolls -= 1
    if flag:
        sum = 1
    return sum
    # END PROBLEM 1


def piggy_points(score):
    """Return the points scored from rolling 0 dice.

    score:  The opponent's current score.
    """
    # BEGIN PROBLEM 2
    squared_score = score ** 2
    min = squared_score % 10
    while squared_score:
        temp = squared_score % 10
        if(temp < min):
            min = temp
        squared_score //= 10
    return min + 3
    # END PROBLEM 2


def take_turn(num_rolls, opponent_score, dice=six_sided, goal=GOAL_SCORE):
    """Simulate a turn rolling NUM_ROLLS dice, which may be 0 in the case
    of a player using Piggy Points.
    Return the points scored for the turn by the current player.

    num_rolls:       The number of dice rolls that will be made.
    opponent_score:  The total score of the opponent.
    dice:            A function that simulates a single dice roll outcome.
    goal:            The goal score of the game.
    """
    # Leave these assert statements here; they help check for errors.
    assert type(num_rolls) == int, 'num_rolls must be an integer.'
    assert num_rolls >= 0, 'Cannot roll a negative number of dice in take_turn.'
    assert num_rolls <= 10, 'Cannot roll more than 10 dice.'
    assert opponent_score < goal, 'The game should be over.'
    # BEGIN PROBLEM 3
    if(num_rolls == 0):
        return piggy_points(opponent_score)
    else:
        return roll_dice(num_rolls, dice)
    # END PROBLEM 3


def more_boar(player_score, opponent_score):
    """Return whether the player gets an extra turn.

    player_score:   The total score of the current player.
    opponent_score: The total score of the other player.

    >>> more_boar(21, 43)
    True
    >>> more_boar(22, 43)
    True
    >>> more_boar(43, 21)
    False
    >>> more_boar(12, 12)
    False
    >>> more_boar(7, 8)
    False
    """
    # BEGIN PROBLEM 4
    '''
    player_leftmost = 0
    player_second_left = 0
    opponent_leftmost = 0
    opponent_second_left = 0
    if(player_score < 10): # catch single digits
        player_second_left = player_score
    else:
        while player_score:
            player_second_left = player_leftmost
            player_leftmost = player_score % 10
            player_score //= 10
    if(opponent_score < 10): # catch single digits
        opponent_second_left = opponent_score
    else:
        while opponent_score:
            opponent_second_left = opponent_leftmost
            opponent_leftmost = opponent_score % 10
            opponent_score //= 10
    return player_leftmost < opponent_leftmost and player_second_left < opponent_second_left
    '''
    # below is so much cleaner
    def get_leftmost_digits(score):
        while score >= 100:
            score //= 10
        return score // 10, score % 10 # tuple with leftmost two digits in order

    player_leftmost, player_second_leftmost = get_leftmost_digits(player_score)
    opponent_leftmost, opponent_second_leftmost = get_leftmost_digits(opponent_score)

    return player_leftmost < opponent_leftmost and player_second_leftmost < opponent_second_leftmost

    # END PROBLEM 4


def next_player(who):
    """Return the other player, for a player WHO numbered 0 or 1.

    >>> next_player(0)
    1
    >>> next_player(1)
    0
    """
    return 1 - who


def silence(score0, score1):
    """Announce nothing (see Phase 2)."""
    return silence


def play(strategy0, strategy1, score0=0, score1=0, dice=six_sided,
         goal=GOAL_SCORE, say=silence):
    """Simulate a game and return the final scores of both players, with Player
    0's score first, and Player 1's score second.

    A strategy is a function that takes two total scores as arguments (the
    current player's score, and the opponent's score), and returns a number of
    dice that the current player will roll this turn.

    strategy0:  The strategy function for Player 0, who plays first.
    strategy1:  The strategy function for Player 1, who plays second.
    score0:     Starting score for Player 0
    score1:     Starting score for Player 1
    dice:       A function of zero arguments that simulates a dice roll.
    goal:       The game ends and someone wins when this score is reached.
    say:        The commentary function to call at the end of the first turn.
    """
    who = 0  # Who is about to take a turn, 0 (first) or 1 (second)
    # BEGIN PROBLEM 5
    scores = {
        0: score0,
        1: score1
    }
    strategies = {
        0: strategy0,
        1: strategy1
    }

    while(scores[0] < goal and scores[1] < goal):
        scores[who] += take_turn(strategies[who](scores[who], scores[1 - who]), scores[1 - who], dice, goal)
        say = say(scores[0], scores[1])
        if(more_boar(scores[who], scores[1 - who])):
            continue # don't change whose turn it is
        who = next_player(who)
    # END PROBLEM 5
    # (note that the indentation for the problem 6 prompt (***YOUR CODE HERE***) might be misleading)
    return scores[0], scores[1]


#######################
# Phase 2: Commentary #
#######################


def say_scores(score0, score1):
    """A commentary function that announces the score for each player."""
    print("Player 0 now has", score0, "and Player 1 now has", score1)
    return say_scores


def announce_lead_changes(last_leader=None):
    """Return a commentary function that announces lead changes.

    >>> f0 = announce_lead_changes()
    >>> f1 = f0(5, 0)
    Player 0 takes the lead by 5
    >>> f2 = f1(5, 12)
    Player 1 takes the lead by 7
    >>> f3 = f2(8, 12)
    >>> f4 = f3(8, 13)
    >>> f5 = f4(15, 13)
    Player 0 takes the lead by 2
    """
    def say(score0, score1):
        if score0 > score1:
            leader = 0
        elif score1 > score0:
            leader = 1
        else:
            leader = None
        if leader != None and leader != last_leader:
            print('Player', leader, 'takes the lead by', abs(score0 - score1))
        return announce_lead_changes(leader)
    return say


def both(f, g):
    """Return a commentary function that says what f says, then what g says.

    NOTE: the following game is not possible under the rules, it's just
    an example for the sake of the doctest

    >>> h0 = both(say_scores, announce_lead_changes())
    >>> h1 = h0(10, 0)
    Player 0 now has 10 and Player 1 now has 0
    Player 0 takes the lead by 10
    >>> h2 = h1(10, 8)
    Player 0 now has 10 and Player 1 now has 8
    >>> h3 = h2(10, 17)
    Player 0 now has 10 and Player 1 now has 17
    Player 1 takes the lead by 7
    """
    def say(score0, score1):
        return both(f(score0, score1), g(score0, score1))
    return say


def announce_highest(who, last_score=0, running_high=0):
    """Return a commentary function that announces when WHO's score
    increases by more than ever before in the game.

    NOTE: the following game is not possible under the rules, it's just
    an example for the sake of the doctest

    >>> f0 = announce_highest(1) # Only announce Player 1 score gains
    >>> f1 = f0(12, 0)
    >>> f2 = f1(12, 9)
    Player 1 has reached a new maximum point gain. 9 point(s)!
    >>> f3 = f2(20, 9)
    >>> f4 = f3(20, 30)
    Player 1 has reached a new maximum point gain. 21 point(s)!
    >>> f5 = f4(20, 47) # Player 1 gets 17 points; not enough for a new high
    >>> f6 = f5(21, 47)
    >>> f7 = f6(21, 77)
    Player 1 has reached a new maximum point gain. 30 point(s)!
    """
    assert who == 0 or who == 1, 'The who argument should indicate a player.'
    # BEGIN PROBLEM 7
    def commentary(score0,score1):
        if who == 0:
            currscore = score0
        else:
            currscore = score1
        difference = currscore-last_score
        if difference > running_high and difference > 0:
            print('Player', who , 'has reached a new maximum point gain.' , difference,'point(s)!')
        return announce_highest(who,currscore,max(running_high,difference))
    return commentary
    # END PROBLEM 7


#######################
# Phase 3: Strategies #
#######################


def always_roll(n):
    """Return a strategy that always rolls N dice.

    A strategy is a function that takes two total scores as arguments (the
    current player's score, and the opponent's score), and returns a number of
    dice that the current player will roll this turn.

    >>> strategy = always_roll(5)
    >>> strategy(0, 0)
    5
    >>> strategy(99, 99)
    5
    """
    def strategy(score, opponent_score):
        return n
    return strategy


def make_averaged(original_function, trials_count=1000):
    """Return a function that returns the average value of ORIGINAL_FUNCTION
    when called.

    To implement this function, you will have to use *args syntax, a new Python
    feature introduced in this project.  See the project description.

    >>> dice = make_test_dice(4, 2, 5, 1)
    >>> averaged_dice = make_averaged(roll_dice, 1000)
    >>> averaged_dice(1, dice)
    3.0
    """
    # BEGIN PROBLEM 8
    def averaged_func(*args):
        result = 0
        k = 0
        while k < trials_count:
            result += original_function(*args)
            k += 1
        return result / trials_count
    return averaged_func
    # END PROBLEM 8


def max_scoring_num_rolls(dice=six_sided, trials_count=1000):
    """Return the number of dice (1 to 10) that gives the highest average turn score
    by calling roll_dice with the provided DICE a total of TRIALS_COUNT times.
    Assume that the dice always return positive outcomes.

    >>> dice = make_test_dice(1, 6)
    >>> max_scoring_num_rolls(dice)
    1
    """
    # BEGIN PROBLEM 9
    running_max = 0
    best_num = 0
    n = 10
    while n:
        result = make_averaged(roll_dice, trials_count)(n, dice)
        if (result > running_max):
            running_max = result
            best_num = n
        n -= 1
    return best_num
    # END PROBLEM 9


def winner(strategy0, strategy1):
    """Return 0 if strategy0 wins against strategy1, and 1 otherwise."""
    score0, score1 = play(strategy0, strategy1)
    if score0 > score1:
        return 0
    else:
        return 1


def average_win_rate(strategy, baseline=always_roll(6)):
    """Return the average win rate of STRATEGY against BASELINE. Averages the
    winrate when starting the game as player 0 and as player 1.
    """
    win_rate_as_player_0 = 1 - make_averaged(winner)(strategy, baseline)
    win_rate_as_player_1 = make_averaged(winner)(baseline, strategy)

    return (win_rate_as_player_0 + win_rate_as_player_1) / 2


def run_experiments():
    """Run a series of strategy experiments and report results."""
    six_sided_max = max_scoring_num_rolls(six_sided)
    print('Max scoring num rolls for six-sided dice:', six_sided_max)
    print('always_roll(6) win rate:', average_win_rate(always_roll(6)))

    #print('always_roll(8) win rate:', average_win_rate(always_roll(8)))
    #print('piggypoints_strategy win rate:', average_win_rate(piggypoints_strategy))
    #print('more_boar_strategy win rate:', average_win_rate(more_boar_strategy))
    #print('final_strategy win rate:', average_win_rate(final_strategy))
    "*** You may add additional experiments as you wish ***"


def piggypoints_strategy(score, opponent_score, cutoff=8, num_rolls=6):
    """This strategy rolls 0 dice if that gives at least CUTOFF points, and
    rolls NUM_ROLLS otherwise.
    """
    # BEGIN PROBLEM 10
    if (piggy_points(opponent_score) >= cutoff):
        return 0
    else:
        return num_rolls
    # END PROBLEM 10


def more_boar_strategy(score, opponent_score, cutoff=8, num_rolls=6):
    """This strategy rolls 0 dice when it triggers an extra turn. It also
    rolls 0 dice if it gives at least CUTOFF points and does not give an extra turn.
    Otherwise, it rolls NUM_ROLLS.
    """
    # BEGIN PROBLEM 11
    if more_boar((score + piggy_points(opponent_score)), opponent_score):
        return 0
    else:
        return piggypoints_strategy(score, opponent_score, cutoff, num_rolls)
    # END PROBLEM 11


def final_strategy(score, opponent_score):
    """Write a brief description of your final strategy.

    *** YOUR DESCRIPTION HERE ***
    """
    # BEGIN PROBLEM 12
    return 6  # Replace this statement
    # END PROBLEM 12

##########################
# Command Line Interface #
##########################

# NOTE: Functions in this section do not need to be changed. They use features
# of Python not yet covered in the course.


@main
def run(*args):
    """Read in the command-line argument and calls corresponding functions."""
    import argparse
    parser = argparse.ArgumentParser(description="Play Hog")
    parser.add_argument('--run_experiments', '-r', action='store_true',
                        help='Runs strategy experiments')

    args = parser.parse_args()

    if args.run_experiments:
        run_experiments()