如何创建随机牌组？

Question

I need to create a deck of cards by using two string: "HSCD" and "A2345678910JQK".

public class Deck {
Random random=new Random();
Queue cards=new Queue(112);
String suits="HSCD";
String rands="A2345678910JQK";

public Deck() {
    for (int i = 0; i < suits.length(); i++) {
        for (int j = 0; j < rands.length(); j++) {
            char suit = suits.charAt(random.nextInt(suits.length()));
            char rand = rands.charAt(random.nextInt(rands.length()));
            if (rand == '1' || rand == '0') {
                String s = Integer.toString(10);
                cards.enqueue(new Card(suit, s));
            } else {
                String s1 = Character.toString(rand);
                cards.enqueue(new Card(suit, s1));
            }
        }
    }
}
public void display(){
    for (int i = 0; i < cards.size(); i++) {
        System.out.print(cards.peek());
        cards.enqueue(cards.dequeue());
    }
}

public Queue getCards() {
    return cards;
}

public void setCards(Queue cards) {
    this.cards = cards;
}

public String getSuits() {
    return suits;
}

public void setSuits(String suits) {
    this.suits = suits;
}

public String getRands() {
    return rands;
}

public void setRands(String rands) {
    this.rands = rands;
}}

I have Deck and Card classes.

public class Card {

private char rand;
private String suit;

public Card(char rand, String suit) {
    this.rand = rand;
    this.suit = suit;
}

public Card(){}

public char getRand() {
    return rand;
}

public void setRand(char rand) {
    this.rand = rand;
}

public String getSuit() {
    return suit;
}

public void setSuit(String suit) {
    this.suit = suit;
}

public String toString(){
    return "\t"+rand + suit;
}}

But i couldn't solve that every suits must have 13 rands. In my program my deck is randomly created. And my deck must be shuffled. I can't use list or array structures because teacher told us so:). Can you help me?

Answer 1

1. You are creating 14 cards per suit, not 13: you're creating 10 twice. Remove with 0 or 1 from rands .

2. It will be easier if you first create the cards, then shuffle them.

Creation of cards should be similar to what you're already doing, minus the randomization - just go through suits and values in order:

for each suit:
  for each value:
    sortedCards.add(new Card(suit, value));

Then, shuffle the cards as follows:

while (sortedCards is not empty):
  shuffledCards.add(sortedCards.get(random.nextInt(sortedCards.size())))

Answer 2

Just duplicate four time the second string. After you take two random numbers one correspond to the sign and one to the number. Finally you put sign+number in memory and you remove the number in the string:

String signs = "HSCD";
String numbersH = "A2345678910JQK";
String numbersS = "A2345678910JQK";
String numbersC = "A2345678910JQK";
String numbersD = "A2345678910JQK";
ArrayList<String> deck = new ArrayList<String>();
Random random = new Random();
while(deck.size()<52){
   int sign = random.nextInt(signs.lenght());
   if(sign==0 && numbersH.lenght()>0){
      int number = random.nextInt(numbersH.lenght());
      deck.add(signs.charAt(sign)+numbersH.charAt(number));
      numbersH = numbersH.substring(0,number)+numberH.substring(number+1);
   }//here the same for other signs

}

Answer 3

You haven't included the Queue class so help is going to be limited. Here are some other suggestions.

        String suits="HSCD";
        String ranks="A23456789TJQK";
        for (int i = 0; i < 52; i++) {
            int suit = i/13; // index into suit 0 to 3 inclusive
            int rank = i%13; // index into rank 0 to 12 inclusive
            cards.enqueue(new Card(suits.charAt(suit), ranks.charAt(rank));
        }

Also, quite often, card game software uses a T for ten, which is what I did in this example. It can be changed but in your implementation you can't store 10 as as a single character and it is cumbersome to maintain two types for card ranks. So you should probably make all your ranks and suits as type String .

Answer 4

Another method: Create your deck like iluxa say you and shuffle with this:

Random rand = new Random();
for(int i=0;i<300;i++){
   int a = rand.nextInt(deck.size());
   int b = rand.nextInt(deck.size());
   Card cA = deck.get(a);
   deck.set(a, deck.get(b));
   deck.set(b, cA);
}

That's code will suffle your deck by switch two random cards many times.