You lost to the small crab! Fortunately, crabs aren’t very good at recursion. To defend your honor as a Raft Captain, you challenge the small crab to a game of Recursive Combat.
Recursive Combat still starts by splitting the cards into two decks (you offer to play with the same starting decks as before — it’s only fair). Then, the game consists of a series of rounds with a few changes:
As in regular Combat, the winner of the round (even if they won the round by winning a sub-game) takes the two cards dealt at the beginning of the round and places them on the bottom of their own deck (again so that the winner’s card is above the other card). Note that the winner’s card might be the lower-valued of the two cards if they won the round due to winning a sub-game. If collecting cards by winning the round causes a player to have all of the cards, they win, and the game ends.
Here is an example of a small game that would loop forever without the infinite game prevention rule:
Player 1:
43
19
Player 2:
2
29
14
During a round of Recursive Combat, if both players have at least as many cards in their own decks as the number on the card they just dealt, the winner of the round is determined by recursing into a sub-game of Recursive Combat. (For example, if player 1 draws the 3
card, and player 2 draws the 7
card, this would occur if player 1 has at least 3 cards left and player 2 has at least 7 cards left, not counting the 3
and 7
cards that were drawn.)
To play a sub-game of Recursive Combat, each player creates a new deck by making a copy of the next cards in their deck (the quantity of cards copied is equal to the number on the card they drew to trigger the sub-game). During this sub-game, the game that triggered it is on hold and completely unaffected; no cards are removed from players’ decks to form the sub-game. (For example, if player 1 drew the 3
card, their deck in the sub-game would be copies of the next three cards in their deck.)
Here is a complete example of gameplay, where Game 1
is the primary game of Recursive Combat:
=== Game 1 ===
-- Round 1 (Game 1) --
Player 1's deck: 9, 2, 6, 3, 1
Player 2's deck: 5, 8, 4, 7, 10
Player 1 plays: 9
Player 2 plays: 5
Player 1 wins round 1 of game 1!
-- Round 2 (Game 1) --
Player 1's deck: 2, 6, 3, 1, 9, 5
Player 2's deck: 8, 4, 7, 10
Player 1 plays: 2
Player 2 plays: 8
Player 2 wins round 2 of game 1!
-- Round 3 (Game 1) --
Player 1's deck: 6, 3, 1, 9, 5
Player 2's deck: 4, 7, 10, 8, 2
Player 1 plays: 6
Player 2 plays: 4
Player 1 wins round 3 of game 1!
-- Round 4 (Game 1) --
Player 1's deck: 3, 1, 9, 5, 6, 4
Player 2's deck: 7, 10, 8, 2
Player 1 plays: 3
Player 2 plays: 7
Player 2 wins round 4 of game 1!
-- Round 5 (Game 1) --
Player 1's deck: 1, 9, 5, 6, 4
Player 2's deck: 10, 8, 2, 7, 3
Player 1 plays: 1
Player 2 plays: 10
Player 2 wins round 5 of game 1!
-- Round 6 (Game 1) --
Player 1's deck: 9, 5, 6, 4
Player 2's deck: 8, 2, 7, 3, 10, 1
Player 1 plays: 9
Player 2 plays: 8
Player 1 wins round 6 of game 1!
-- Round 7 (Game 1) --
Player 1's deck: 5, 6, 4, 9, 8
Player 2's deck: 2, 7, 3, 10, 1
Player 1 plays: 5
Player 2 plays: 2
Player 1 wins round 7 of game 1!
-- Round 8 (Game 1) --
Player 1's deck: 6, 4, 9, 8, 5, 2
Player 2's deck: 7, 3, 10, 1
Player 1 plays: 6
Player 2 plays: 7
Player 2 wins round 8 of game 1!
-- Round 9 (Game 1) --
Player 1's deck: 4, 9, 8, 5, 2
Player 2's deck: 3, 10, 1, 7, 6
Player 1 plays: 4
Player 2 plays: 3
Playing a sub-game to determine the winner...
=== Game 2 ===
-- Round 1 (Game 2) --
Player 1's deck: 9, 8, 5, 2
Player 2's deck: 10, 1, 7
Player 1 plays: 9
Player 2 plays: 10
Player 2 wins round 1 of game 2!
-- Round 2 (Game 2) --
Player 1's deck: 8, 5, 2
Player 2's deck: 1, 7, 10, 9
Player 1 plays: 8
Player 2 plays: 1
Player 1 wins round 2 of game 2!
-- Round 3 (Game 2) --
Player 1's deck: 5, 2, 8, 1
Player 2's deck: 7, 10, 9
Player 1 plays: 5
Player 2 plays: 7
Player 2 wins round 3 of game 2!
-- Round 4 (Game 2) --
Player 1's deck: 2, 8, 1
Player 2's deck: 10, 9, 7, 5
Player 1 plays: 2
Player 2 plays: 10
Player 2 wins round 4 of game 2!
-- Round 5 (Game 2) --
Player 1's deck: 8, 1
Player 2's deck: 9, 7, 5, 10, 2
Player 1 plays: 8
Player 2 plays: 9
Player 2 wins round 5 of game 2!
-- Round 6 (Game 2) --
Player 1's deck: 1
Player 2's deck: 7, 5, 10, 2, 9, 8
Player 1 plays: 1
Player 2 plays: 7
Player 2 wins round 6 of game 2!
The winner of game 2 is player 2!
...anyway, back to game 1.
Player 2 wins round 9 of game 1!
-- Round 10 (Game 1) --
Player 1's deck: 9, 8, 5, 2
Player 2's deck: 10, 1, 7, 6, 3, 4
Player 1 plays: 9
Player 2 plays: 10
Player 2 wins round 10 of game 1!
-- Round 11 (Game 1) --
Player 1's deck: 8, 5, 2
Player 2's deck: 1, 7, 6, 3, 4, 10, 9
Player 1 plays: 8
Player 2 plays: 1
Player 1 wins round 11 of game 1!
-- Round 12 (Game 1) --
Player 1's deck: 5, 2, 8, 1
Player 2's deck: 7, 6, 3, 4, 10, 9
Player 1 plays: 5
Player 2 plays: 7
Player 2 wins round 12 of game 1!
-- Round 13 (Game 1) --
Player 1's deck: 2, 8, 1
Player 2's deck: 6, 3, 4, 10, 9, 7, 5
Player 1 plays: 2
Player 2 plays: 6
Playing a sub-game to determine the winner...
=== Game 3 ===
-- Round 1 (Game 3) --
Player 1's deck: 8, 1
Player 2's deck: 3, 4, 10, 9, 7, 5
Player 1 plays: 8
Player 2 plays: 3
Player 1 wins round 1 of game 3!
-- Round 2 (Game 3) --
Player 1's deck: 1, 8, 3
Player 2's deck: 4, 10, 9, 7, 5
Player 1 plays: 1
Player 2 plays: 4
Playing a sub-game to determine the winner...
=== Game 4 ===
-- Round 1 (Game 4) --
Player 1's deck: 8
Player 2's deck: 10, 9, 7, 5
Player 1 plays: 8
Player 2 plays: 10
Player 2 wins round 1 of game 4!
The winner of game 4 is player 2!
...anyway, back to game 3.
Player 2 wins round 2 of game 3!
-- Round 3 (Game 3) --
Player 1's deck: 8, 3
Player 2's deck: 10, 9, 7, 5, 4, 1
Player 1 plays: 8
Player 2 plays: 10
Player 2 wins round 3 of game 3!
-- Round 4 (Game 3) --
Player 1's deck: 3
Player 2's deck: 9, 7, 5, 4, 1, 10, 8
Player 1 plays: 3
Player 2 plays: 9
Player 2 wins round 4 of game 3!
The winner of game 3 is player 2!
...anyway, back to game 1.
Player 2 wins round 13 of game 1!
-- Round 14 (Game 1) --
Player 1's deck: 8, 1
Player 2's deck: 3, 4, 10, 9, 7, 5, 6, 2
Player 1 plays: 8
Player 2 plays: 3
Player 1 wins round 14 of game 1!
-- Round 15 (Game 1) --
Player 1's deck: 1, 8, 3
Player 2's deck: 4, 10, 9, 7, 5, 6, 2
Player 1 plays: 1
Player 2 plays: 4
Playing a sub-game to determine the winner...
=== Game 5 ===
-- Round 1 (Game 5) --
Player 1's deck: 8
Player 2's deck: 10, 9, 7, 5
Player 1 plays: 8
Player 2 plays: 10
Player 2 wins round 1 of game 5!
The winner of game 5 is player 2!
...anyway, back to game 1.
Player 2 wins round 15 of game 1!
-- Round 16 (Game 1) --
Player 1's deck: 8, 3
Player 2's deck: 10, 9, 7, 5, 6, 2, 4, 1
Player 1 plays: 8
Player 2 plays: 10
Player 2 wins round 16 of game 1!
-- Round 17 (Game 1) --
Player 1's deck: 3
Player 2's deck: 9, 7, 5, 6, 2, 4, 1, 10, 8
Player 1 plays: 3
Player 2 plays: 9
Player 2 wins round 17 of game 1!
The winner of game 1 is player 2!
== Post-game results ==
Player 1's deck:
Player 2's deck: 7, 5, 6, 2, 4, 1, 10, 8, 9, 3
After the game, the winning player’s score is calculated from the cards they have in their original deck using the same rules as regular Combat. In the above game, the winning player’s score is 291
.
Defend your honor as Raft Captain by playing the small crab in a game of Recursive Combat. What is the winning player’s score? Determine this in the following way:
winningScore
that takes the pathname (String
) of a text file containing the decks dealt to both players. The function must return the winning player’s score (Int
).In this interactive session we assume the text file decks.txt
1 to be located in the current directory.
> winningScore("decks.txt")
291