public boolean play()
// Simulates one game. If number of battles played
// reaches maxNumBattles, the game is discontinued.
// Returns true if game finishes normally; returns false
// if game is discontinued.
{
// instantiate players' hands
player1 = new ArrayBndQueue<Integer>(numCards);
player2 = new ArrayBndQueue<Integer>(numCards);
// instantiate prize pile
prize = new ArrayBndQueue<Integer>(numCards);
boolean gameOver = false; // becomes true when the game is over
boolean gameOK = true; // becomes false if game is discontinued
// deal original hands
deck.shuffle();
while (deck.hasMoreCards()) {
player1.enqueue(deck.nextCard());
if (deck.hasMoreCards()) player2.enqueue(deck.nextCard());
}
// play game until somebody runs out of cards or
// reach the maximum number of battles
numBattles = 0;
while (!gameOver) {
try {
numBattles = numBattles + 1;
battle();
} catch (QueueUnderflowException exceptionVar) {
gameOver = true;
}
if (numBattles == maxNumBattles) {
gameOver = true;
gameOK = false;
}
}
return gameOK;
}
private void battle()
// Models a battle between player1 and player2. If the battle
// results in a war, three cards from each player are placed
// in the prize queue and the battle is continued recursively.
{
// cards for this battle
int p1card;
int p2card;
// get cards from players and place in prize queue
p1card = player1.dequeue();
prize.enqueue(p1card);
p2card = player2.dequeue();
prize.enqueue(p2card);
// determine and handle result of battle
if (p1card > p2card) // player 1 wins
while (!prize.isEmpty()) player1.enqueue(prize.dequeue());
else {
if (p2card > p1card) // player 2 wins
while (!prize.isEmpty()) player2.enqueue(prize.dequeue());
else {
// it's a war ...
// each player places 3 cards in prize pile
for (int i = 0; i < 3; i++) {
prize.enqueue(player1.dequeue());
prize.enqueue(player2.dequeue());
}
// now continue the battle to determine who wins prize
battle();
}
}
}