The Game of Hog

2022.01.15

每天下班抠一点时间出来写,听课的时候higher-order functions没怎么看明白,感觉像懂了,写到phase 2的几问才发现根本没懂再回去补课。整体写起来很有意思,目前的胜率是0.5496381517033135,题目里给的hint只用了一个,如果之后有兴趣再研究看看怎么提高胜率

题目链接(2019 fall)

粗糙的代码也存个档


"""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
    sum_out = 0
    terms = 0
    pig_flag = False
    while terms < num_rolls:
        outcome = dice()
        if outcome == 1:
            pig_flag = True
        else:
            sum_out = sum_out + outcome
        terms = terms + 1
    if pig_flag == True:
        return 1
    else:
        return sum_out
    # END PROBLEM 1
 
 
def free_bacon(score):
    """Return the points scored from rolling 0 dice (Free Bacon).
 
    score:  The opponent's current score.
    """
    assert score < 100, 'The game should be over.'
    # BEGIN PROBLEM 2
    f_score = 0
    tens = 0
    ones = 0
    if score < 10:
        f_score = 10
    else:
        tens = score // 10
        ones = score % 10
        f_score = 10 - min(tens, ones)
    return f_score
    # END PROBLEM 2
 
 
def take_turn(num_rolls, opponent_score, dice=six_sided):
    """Simulate a turn rolling NUM_ROLLS dice, which may be 0 (Free Bacon).
    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.
    """
    # 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 < 100, 'The game should be over.'
    # BEGIN PROBLEM 3
    if num_rolls != 0:
        turn_score = roll_dice(num_rolls, dice)
    else:
        turn_score = free_bacon(opponent_score)
    return turn_score
    # END PROBLEM 3
 
 
def is_swap(player_score, opponent_score):
    """
    Return whether the two scores should be swapped
    """
    # BEGIN PROBLEM 4
    last_player = player_score % 10
    last_opp = opponent_score % 10
    while player_score // 10 != 0:
        player_score = player_score // 10
    first_player = player_score % 10
    while opponent_score // 10 != 0:
        opponent_score = opponent_score // 10
    first_opp = opponent_score % 10
    if first_player * last_player == first_opp * last_opp:
        return True
    else:
        return False
    # END PROBLEM 4
 
 
def other(player):
    """Return the other player, for a player PLAYER numbered 0 or 1.
 
    >>> other(0)
    1
    >>> other(1)
    0
    """
    return 1 - player
 
 
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, feral_hogs=True):
    """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 015
    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.
    feral_hogs: A boolean indicating whether the feral hogs rule should be active.
    """
    player = 0  # Which player is about to take a turn, 0 (first) or 1 (second)
    # BEGIN PROBLEM 5
    num_rolls_pre0 = 0
    num_rolls_pre1 = 0
    while score0 < goal and score1 < goal:
        if player == 0:
            num_rolls = strategy0(score0, score1)
            score0 += take_turn(num_rolls, score1, dice)
            if abs(num_rolls - num_rolls_pre0) == 2:
                score0 = score0 + 3
            num_rolls_pre0 = num_rolls
        else:
            num_rolls = strategy1(score1, score0)
            score1 += take_turn(num_rolls, score0, dice)
            if abs(num_rolls - num_rolls_pre1) == 2:
                score1 = score1 + 3
            num_rolls_pre1 = num_rolls
        if is_swap(score0, score1) == True:
            score0, score1 = score1, score0
        say = say(score0, score1)
        player = other(player)
    return score0, score1
 
 
#######################
# 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(previous_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 != previous_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, 6)
    Player 0 now has 10 and Player 1 now has 6
    >>> h3 = h2(6, 17)
    Player 0 now has 6 and Player 1 now has 17
    Player 1 takes the lead by 11
    """
    def say(score0, score1):
        return both(f(score0, score1), g(score0, score1))
    return say
 
 
def announce_highest(who, previous_high=0, previous_score=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, 11)
    11 point(s)! That's the biggest gain yet for Player 1
    >>> f3 = f2(20, 11)
    >>> f4 = f3(13, 20)
    >>> f5 = f4(20, 35)
    15 point(s)! That's the biggest gain yet for Player 1
    >>> f6 = f5(20, 47) # Player 1 gets 12 points; not enough for a new high
    >>> f7 = f6(21, 47)
    >>> f8 = f7(21, 77)
    30 point(s)! That's the biggest gain yet for Player 1
    >>> f9 = f8(77, 22) # Swap!
    >>> f10 = f9(33, 77) # Swap!
    55 point(s)! That's the biggest gain yet for Player 1
    """
    assert who == 0 or who == 1, 'The who argument should indicate a player.'
    def say(score0, score1, previous_score=previous_score, previous_high=previous_high):
        if who == 0:
            climb = score0 - previous_score
            previous_score = score0
        else:
            climb = score1 - previous_score
            previous_score = score1
        if climb > previous_high:
            previous_high = climb
            print(climb, 'point(s)! That\'s the biggest gain yet for Player', who)
        return announce_highest(who, previous_high, previous_score)
    return say
 
 
#######################
# 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(fn, num_samples=1000):
    """Return a function that returns the average value of FN 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(dice, 1000)
    >>> averaged_dice()
    3.0
    """
    # BEGIN PROBLEM 8
    def average_value(*args):
        result, average = 0, 0
        k = 0
        while k < num_samples:
            result += fn(*args)
            k += 1
        average = result / num_samples
        return average
    return average_value
    # END PROBLEM 8
 
 
def max_scoring_num_rolls(dice=six_sided, num_samples=1000):
    """Return the number of dice (1 to 10) that gives the highest average turn
    score by calling roll_dice with the provided DICE over NUM_SAMPLES times.
    Assume that the dice always return positive outcomes.
 
    >>> dice = make_test_dice(1, 6)
    >>> max_scoring_num_rolls(dice)
    1
    """
    # BEGIN PROBLEM 9
    roll = 10
    max_average = 0
    max_roll = 10
    while roll > 0:
        turn_average = make_averaged(roll_dice, num_samples)(roll, dice)
        if turn_average >= max_average:
            max_average = turn_average
            max_roll = roll
        roll -= 1
    return max_roll
    # 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(4)):
    """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."""
    if True:  # Change to False when done finding max_scoring_num_rolls
        six_sided_max = max_scoring_num_rolls(six_sided)
        print('Max scoring num rolls for six-sided dice:', six_sided_max)
 
    if False:  # Change to True to test always_roll(8)
        print('always_roll(6) win rate:', average_win_rate(always_roll(6)))
 
    if False:  # Change to True to test bacon_strategy
        print('bacon_strategy win rate:', average_win_rate(bacon_strategy))
 
    if False:  # Change to True to test swap_strategy
        print('swap_strategy win rate:', average_win_rate(swap_strategy))
 
    if False:  # Change to True to test final_strategy
        print('final_strategy win rate:', average_win_rate(final_strategy))
 
    "*** You may add additional experiments as you wish ***"
 
 
def bacon_strategy(score, opponent_score, margin=8, num_rolls=4):
    """This strategy rolls 0 dice if that gives at least MARGIN points, and
    rolls NUM_ROLLS otherwise.
    """
    # BEGIN PROBLEM 10
    if free_bacon(opponent_score) >= margin:
        return 0
    else:
        return num_rolls 
    # END PROBLEM 10
 
 
def swap_strategy(score, opponent_score, margin=8, num_rolls=4):
    """This strategy rolls 0 dice when it triggers a beneficial swap. It also
    rolls 0 dice if it gives at least MARGIN points and does not trigger a
    non-beneficial swap. Otherwise, it rolls NUM_ROLLS.
    """
    # BEGIN PROBLEM 11
    bacon_score = free_bacon(opponent_score)
    add_score = score + bacon_score
    if is_swap(add_score, opponent_score) and add_score < opponent_score:
        return 0
    elif bacon_score >= margin:
        if is_swap(add_score, opponent_score) and score > opponent_score:
            return num_rolls
        else:
            return 0
    else:
        return num_rolls
    # END PROBLEM 11
 
 
def final_strategy(score, opponent_score):
    """Write a brief description of your final strategy.
 
    *** YOUR DESCRIPTION HERE ***
    """
    dice = swap_strategy(score, opponent_score, margin=9, num_rolls=5) 
    return dice
 
 
##########################
# 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.
 
    This function uses Python syntax/techniques not yet covered in this course.
    """
    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()
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