NineCards.py

from random import shuffle

total_moves = 0
push_moves = 0

def play_round():
    global total_moves
    global push_moves
    deck = 4 * [2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14]
    shuffle(deck)
    print(deck)
    board = []
    last_slot = 100
    same_slot_count = 0
    locked_slot = False
    for i in range(9):
        board.append(deck.pop())
    print(board)
    while len(deck) != 0:
        # Try to place a card
        probabilities = [(probability_higher(deck, slot), probability_same(deck, slot), probability_lower(deck, slot)) for slot in board]
        best_probability = 0
        best_slot = 0
        best_move = ''
        if locked_slot:
            best_slot = last_slot
            number = board[best_slot]
            high, same, low = (probability_higher(deck, number), probability_same(deck, number), probability_lower(deck, number))
            if max(high, same, low) == high:
                best_move = 'high'
            elif max(high, same, low) == same:
                best_move = 'push'
            elif max(high,same, low) == low:
                best_move = 'low'
        else:
            for idx, slot in enumerate(probabilities):
                if slot != 'X':
                    if slot[0] > best_probability:
                        best_probability = slot[0]
                        best_slot = idx
                        best_move = 'high'
                    elif slot[1] > best_probability:
                        best_probability = slot[1]
                        best_slot = idx
                        best_move = 'push'
                    elif slot[2] > best_probability:
                        best_probability = slot[2]
                        best_slot = idx
                        best_move = 'low'
        next_card = deck.pop()
        print("Next card: {}, slot {}, slotted card: {}, action: {}".format(next_card, best_slot, board[best_slot], best_move))
        if last_slot == best_slot:
            same_slot_count += 1
            if same_slot_count == 2:
                # second card is same_slot_count = 1, 2 is when the third card is played and we're locked in
                locked_slot = True
                print("Locked in on slot {}".format(last_slot))
        else:
            same_slot_count = 0
            last_slot = best_slot

        total_moves += 1

        if best_move == 'high':
            if next_card > board[best_slot]:
                board[best_slot] = next_card
            else:
                locked_slot = False
                board[best_slot] = 'X'
        elif best_move == 'push':
            push_moves += 1
            if next_card == board[best_slot]:
                board[best_slot] = next_card
            else:
                locked_slot = False
                board[best_slot] = 'X'
        elif best_move == 'low':
            if next_card < board[best_slot]:
                board[best_slot] = next_card
            else:
                locked_slot = False
                board[best_slot] = 'X'
        print(board)
        if all(x == 'X' for x in board):
            print("failed attempt, {} cards left".format(len(deck)))
            return False

    return True



def probability_higher(deck, number):
    if number == 'X':
        return 0
    total = len(deck)
    higher = len([x for x in deck if x > number])
    return higher / total


def probability_lower(deck, number):
    if number == 'X':
        return 0
    total = len(deck)
    lower = len([x for x in deck if x < number])
    return lower / total


def probability_same(deck, number):
    if number == 'X':
        return 0
    total = len(deck)
    same = len([x for x in deck if x == number])
    return same / total


success = 0
failure = 0
for i in range(10000):
    result = play_round()
    if result:
        success += 1
    else:
        failure += 1
print("Successes: {}, failures: {}".format(success, failure))
print("Total moves: {}, push moves: {}".format(total_moves, push_moves))