今天面试遇到了雷人面试题求解

有问题吧，并发访问可能会出现有人多牌，有人少牌的情况。

不雷人呀，感觉很简单，没什么亮点的题。。

public static void main(String[] args) {
		String[] suits = { "方片", "梅花", "红桃", "黑桃" };
		String[] cardValues = { "A", "2", "3", "4", "5", "6", "7", "8", "9",
				"10", "J", "Q", "K" };

		int cardsInDeck = 52;
		Vector<String> deck = new Vector<String>(cardsInDeck);
		LinkedList<String> shuffledDeck = new LinkedList<String>();
		Random chooser = new Random(); // Card chooser
				
		// Load the deck
		for (String suit : suits) {
			for (String cardValue : cardValues) {
				deck.add(suit+cardValue);
			}
		}

		// Select cards at random from the deck to transfer to shuffled deck
		int selection = 0; // Selected card index
		for (int i = 0; i < cardsInDeck; i++) {
			selection = chooser.nextInt(deck.size());
			shuffledDeck.add(deck.remove(selection));
		}
		// Deal the cards from the shuffled deck into four hands
		StringBuffer[] hands = { new StringBuffer("Hand 1:"),
				new StringBuffer("Hand 2:"), new StringBuffer("Hand 3:"),
				new StringBuffer("Hand 4:") };
		ListIterator cards = shuffledDeck.listIterator();

		while (cards.hasNext()) {
			for (StringBuffer hand : hands) {
				hand.append(' ').append((String) (cards.next()));
			}
		}

		// Display the hands
		for (StringBuffer hand : hands) {
			System.out.println(hand.toString());
		}
	}

生成随机数算法吧~~

不错的想法 ....支持

模拟下现实的场景是先买来一副牌，然后搓牌，然后轮流一张张发给4个人，反正已经搓过了，所以每人一口气拿13张效果也是随机的。

 public static void main(String[] args) {
  List<Long> list = new ArrayList<Long>();
  // 生成52张牌
  for (Long i = 1L; i < 53L; i++) {
   list.add(i);
  }
  // 把牌打乱
  Collections.shuffle(list);
  // 给4个人发牌,52/4=13 ，每13张牌就换行输出
  for (int i = 0; i < list.size(); i++) {
   System.out.print(list.get(i));
   if ((i + 1) % 13 == 0) {
    System.out.println();
   } else {
    System.out.print(",");
   }
  }

 }

}

晕的很。。。。 这个不难吧。。
    还是太简单了呢。。。
http://qianlei007.iteye.com/blog/201674
我写的。

最重要的是伪随机数有可能会产生胜率偏向

写得很简单：
public class Test {

  public static void main(String[] args) throws InterruptedException {
    Cards cards = new Cards();
    Person person1 = new Person(cards,"persion1");
    Person person2 = new Person(cards,"persion2");
    Person person3 = new Person(cards,"persion3");
    Person person4 = new Person(cards,"persion4");
   
    person1.start();
    person2.start();
    person3.start();
    person4.start();
   
    person1.join();
    person2.join();
    person3.join();
    person4.join();
   
    person1.show();
    person2.show();
    person3.show();
    person4.show();
  }
}

class Cards{
  int[][] cards = new int[4][13];
  int color = 0;
  int count = 0;
  protected Cards() {
    initialize();
  }
 
  protected void initialize(){
  for (int i=0; i < 4; i++){
    for (int j=1; j <= 13; j++){
      cards[i][j-1] = j;
    }
  }
  }
 
  synchronized int getCard(){
    if (color >= 4){
      throw new IllegalStateException("No card.");
    }
   
    int car = cards[color][count];
    count ++;
    if (count >=13){
      color ++;
      count = 0;
    }
   
   
    return car;
  }
}

class Person extends Thread{
  int[]  personalCards = new int[13];
  int count = 0;
  Cards cards =null;
 
  Person (Cards argCards, String argThreadName){
    super(argThreadName);
    cards = argCards;
  }
  /** {@inheritDoc} */
  @Override
  public void run() {
    while (count < 13){
      personalCards[count] =  cards.getCard();
      count++;
    }
  }
 
  public void show() {
    System.out.println();
    System.out.println(this.getName()+":");
    for (int i : personalCards){
      System.out.print(i + ", ");
    }
  }
}

运行结果：
persion1:
1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13,
persion2:
1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13,
persion3:
1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13,
persion4:
1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13,