Project Euler, no. 84, http://projecteuler.net/problem=84

monopoly.py

import random

board = ["GO", "A1", "CC1", "A2", "T1", "R1", "B1", "CH1", "B2", "B3", "JAIL",
    "C1", "U1", "C2", "C3", "R2", "D1", "CC2", "D2", "D3", "FP",
    "E1", "CH2", "E2", "E3", "R3", "F1", "F2", "U2", "F3", "G2J",
    "G1", "G2", "CC3", "G3", "R4", "CH3", "H1", "T2", "H2"]
double_board = board * 2
visits = [0] * len(board)

cc_cards = ["GO", "JAIL"] + ["NOP"] * 14
ch_cards = ["GO", "JAIL", "C1", "E3", "H2", "R1", "R*", "R*", "U*", "-3"] + ["NOP"] * 6
random.shuffle(cc_cards)
random.shuffle(ch_cards)
double_rolls = [0, 0, 0]


def is_double_roll((x, y)):
    return x == y


def three_double_rolls():
    global double_rolls  # :S
    go_jail = sum(double_rolls) == 3
    if go_jail:
        double_rolls = [0, 0, 0]
    return go_jail


def two_dice():
    double_rolls.pop(0)
    dice = (random.randint(1, 6), random.randint(1, 6))
    if is_double_roll(dice):
        double_rolls.append(1)
    else:
        double_rolls.append(0)
    return dice


def get_next_card(deck):
    top = deck.pop(0)
    deck.append(top)
    return top


def lookup(board_name, current_pos):
    return board.index(board_name)


def step(current_pos, step):
    return (current_pos + step) % len(board)


def linear_search(from_pos, lead):
    pos = from_pos + 1
    while not double_board[pos].startswith(lead):
        pos += 1
    return step(pos, 0)


def card_action(current_pos, card):
    if card in board:
        return lookup(card, current_pos)
    else:
        if card == "NOP":
            return current_pos
        if card == "-3":
            return step(current_pos, -3)
        return linear_search(current_pos, card[0])


def advance_once(current_pos):
    if three_double_rolls():
        return lookup("JAIL", current_pos)
    if board[current_pos] == "G2J":
        return lookup("JAIL", current_pos)
    if board[current_pos][:2] == "CC":
        return card_action(current_pos, get_next_card(cc_cards))
    if board[current_pos][:2] == "CH":
        return card_action(current_pos, get_next_card(ch_cards))
    return current_pos


def advance(current_pos):
    prev = current_pos
    next = advance_once(prev)
    while next != prev:
        prev = next
        next = advance_once(prev)
    return next


def move(current_pos):
    steps = sum(two_dice())
    new_pos = step(current_pos, steps)
    new_pos = advance(new_pos)
    visits[new_pos] += 1
    return new_pos

count = 10000
pos = 0
for i in range(count):
    pos = move(pos)


probs = [100 * v / float(count) for v in visits]
print probs
print "JAIL (6.24%): {val}".format(val=probs[10])
print "E3   (3.18%): {val}".format(val=probs[24])
print "GO   (3.09%): {val}".format(val=probs[0])
print "G2J  (0.00%): {val}".format(val=probs[30])
result = list(reversed(sorted(zip(probs, range(0, len(probs))))))
print result
print "".join(map(lambda (x, y): ("00" + str(y))[-2:], result[:3]))