0 1 2 3 4 5 6 7 8 9 10
39 11
38 12
37 13
36 14
35 15
34 16
33 17
32 18
31 19
30 29 28 27 26 25 24 23 22 21 20
In a certain board game, there are 40 numbered squares arranged around the board as shown above. The players alternate
turns. On each turn a player rolls 2 six-sided dice and moves forward (clockwise) the sum of the
two values. If he lands on square 7, 22, or 36 he draws a card which may direct him
to move forward to a specified square or to "go to jail". There are 20 cards, and after a card has been drawn it is replaced and the cards are reshuffled: -
2 cards say "go to jail"
-
1 card says "go to square 11"
-
1 card says "go to square 24"
-
1 card says "go to square 29"
-
1 card says "go to square 39"
-
14 cards don't cause him to move
If he has not gone to jail and has rolled "doubles" (the 2 dice have the same value) he
continues his turn by rolling again and behaving as before. However, if he rolls doubles
3 times on one turn, he does not move the amount shown on the third roll -- instead
he "goes to jail".
The player's turn ends after he moves on a roll that was not doubles, or when he goes to jail.
One additional rule is that if a player lands on square 30, his turn ends after that move and he goes to jail.
We want to analyze the beginning of a 2 player game. Both players start on square 0. We will pretend that a
player is removed from the game when he goes to jail or when he gets past square 39 (possibly
by being directed to move by a card). So if a card directs a player to a lower numbered square, the player is
removed from the game before landing on that square. If a card directs a player to a higher numbered square, he
has landed on both the square where he drew the card and on the square he was directed to.
For a particular square we want to know the probability that the 2nd player will land on it without
having the first player land on it earlier. Create a class Monopolies that contains a method
probability the is given square and that returns the desired probability.
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