混洗甲板算法

Question

我有以下的java代碼，應該在卡組中「洗牌」牌。甲板是一個包含卡片對象的陣列列表。

private void ShuffleDeck() { 
    //Number of cards in deck 
    int deckSize = deck.size(); 

    //Swapping 100 cards 
    for(int i = 0; i < 15; i++) { 

     //Generating two random card indexes 
     int indexA = (int) ((Math.random() * deckSize-1)); 
     int indexB = (int) (Math.random() * deckSize-1); 
     System.out.println(indexA + " " + indexB); 

     //Getting objects 
     Card cardA = deck.get(indexA); 
     Card cardB = deck.get(indexB); 

     //Temporaily removing these cards from deck 
     deck.remove(cardA); 
     deck.remove(cardB); 

     //Swapping around the two cards 
     deck.add(indexA, cardB); 
     deck.add(indexB, cardA); 

    } 

} 

然而，當我運行這個方法有些卡似乎從甲板上「消失」 ......任何建議，這是爲什麼？ :)

Answer 1

假設deck是List<Card>（包括ArrayList等）：

public void shuffleDeck() { // please use camelCase method names 
    Collections.shuffle(deck); 
} 

不要重新發明輪子。