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();
      }
    }
  }
  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;
  }