Poker Hands in Java

Is there any easy method t开发者_开发百科o compare two poker hands? I'm going about this pretty naively, so if anybody has experience doing this, it could be helpful.

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There isn't an easy (and performant) way to do this, especially if you want to evaluate five-card subsets of seven-card hands, like in Texas Hold 'em.

You might want to check out pokersource which has some Java bindings.

Edit - an additional resource is the pokerai forums. I found quite a few Java algorithms there. They are regularly run through benchmarks and are often accompanied by enumeration algorithms for Monte Carlo simulation. This appears to be the main post.

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I found this which seems promising.

You can also roll your own.

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An example of a ready made Texas Hold'em 7- and 5-card evaluator can be found here with documentation and further explained here. All feedback welcome at the e-mail address found therein.

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Look at this free poker java lib from Alberta university : http://spaz.ca/poker/doc/ca/ualberta/cs/poker/package-summary.html

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Assuming you already have some kind of data structure in place for determining the kind of hand that the player has, you could just assign some kind of int value to each type of hand and compare them. Whatever player has the higher value wins. If the values are equal, you'd just have to compare the hands against eachother. I.E if both have pairs, just compare the numbers of the card, or if they have a full house, compare the value of the card that they have 3 of.

EDIT: if they have the same hand, just check the next highest card in their hand (kicker).

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I wrote a poker hand evaluation library for java, that does exactly what your looking for. It wasn't easy but it is performant. I released it under the GNU GPL on GitHub.

get sourecode here

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I wrote this, let me know if this helps. Essentially I map each card to a number 2 of spades being 0,and Ace of spades being a 12 and 2 of hearts a 3 etc etc. I wish I saw this thread before I put in the work.

  /**
     * Takes any subset of numberCards and creates an array which directly says
     * how good the cards are This method is long so If it is working try not to
     * tweak it TODO potential re-factor
     *
     * @todo Fix this @fixMe
     * @param cards to analyze
     * @return condensed form of hand in the format(tier, High Card, High Card
     * 2,Kicker(s),sometimes some zeroes)
     */
    public static int[] analyzeCards(int[] cards) {
        int suitFlush = 0;
        int[] unsuitedCards = new int[cards.length];
        for (int i = 0; i < cards.length; i++) {
            unsuitedCards[i] = (cards[i] % 13);
        }
                Arrays.sort(unsuitedCards);
        unsuitedCards = reverse(unsuitedCards);
 //converting cards into just numbers 0-12 in descending order

        
        int[] lookForPairsHere=unsuitedCards.clone();

//        System.out.println(Arrays.toString(unsuitedCards));
        //defining the suits of the cards 0,1,2,3
        // and the suits are in order of the cards
        int[] suitsOfCards = new int[cards.length];
        for (int i = 0; i < cards.length; i++) {
            suitsOfCards[i] = cards[i] / 13;
        }
        int[] numberOfEachValuedCard = {0, 0, 0, 0, 0, 0, 0,
            0, 0, 0, 0, 0, 0};
        int[] pairs = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0};

        lookForPairsHere = unsuitedCards.clone();

        int[] originalCards = cards.clone();
        int[] condensedCards = {0, -1, 0, 0, 0, 0};
        int[] suits = {0, 0, 0, 0};
        boolean[] hasQuality = {false, false}; // hasQuality[0] is flush and 
        //hasQuality[1] is a straight
        for (int i = 0; i < suitsOfCards.length; i++) {
            suits[suitsOfCards[i]]++;
        }
        for (int i = 0; i < 4; i++) {
            if (suits[i] > 4) {
                hasQuality[0] = true;
//                System.out.println("flush");
                // there is a flush!
                suitFlush = i;
                }
        }
int[] straightCards = {-2, -2, -2, -2, -2, -2, -2};
        int i = 0;
        int j = 1;
        int card = 0;
//        some iterators I will need to keep track of temporarily
//         i is just an iterator j is the number of consecuetive cards

if(hasQuality[0]){
        for (i = 0; i <originalCards.length; i++) {
                if (originalCards[i]/13 == suitFlush) {
                    straightCards[i] = originalCards[i];
                }
            }
Arrays.sort(straightCards);
straightCards=reverse(straightCards);
//sorting flushCards in order;
        unsuitedCards = removeDuplicates(unsuitedCards);
        // getting rid of duplicates to prevent trouble
condensedCards[1]=straightCards[0]%13;
}
        if (/*there is not a flush already*/!hasQuality[0]) {
                for(i=0;(i<unsuitedCards.length-5);i++){
                    if(unsuitedCards[i]-1==unsuitedCards[i+1]&&
                            unsuitedCards[i]-2==unsuitedCards[i+2]&&
                            unsuitedCards[i]-3==unsuitedCards[i+3]&&
                            unsuitedCards[i]-4==unsuitedCards[i+4]){
                        hasQuality[1]=true;
                        condensedCards[1]=unsuitedCards[i];
                }
                }
            if (hasQuality[1] == false) {
                int b = 0;
                if (unsuitedCards[0] == 12) {
                    //looks for ace-5 flush
                    for (i = 0; i < unsuitedCards.length; i++) {
                        if (unsuitedCards[i] == 3 || unsuitedCards[i] == 2 || unsuitedCards[i] == 1
                                || unsuitedCards[i] == 0) {
                            b++;
                        }
                    }
                    if (b>3) {
                        hasQuality[1] = true;
                        //there is an ace-5 flush
                        condensedCards[1] = 3;
                    }
                }
            }
        } else/*there is a flush already so a straight is suited*/ {
            Arrays.sort(straightCards);
            straightCards = reverse(straightCards);
            //order it
            // look for A normal straight    
            for(i=0;(i<straightCards.length-5);i++){
                    if(straightCards[i]-1==straightCards[i+1]&&
                            straightCards[i]-2==straightCards[i+2]&&
                            straightCards[i]-3==straightCards[i+3]&&
                            straightCards[i]-4==straightCards[i+4]){
                        hasQuality[1]=true;
                        condensedCards[1]=straightCards[i];
                }
            }
            if (hasQuality[1] == false) {
                int b = 0;
                if (straightCards[0] == 12) {
                    //looks for ace-5 flush
                    for (int z = 0; (z< straightCards.length); z++){
                        if (straightCards[z] == 3 || straightCards[z] == 2 || 
                                straightCards[z] == 1
                                ||straightCards[z] == 0) {
                            b++;
                        }
                    }
                    if (b>3) {
                        hasQuality[1] = true;
                        //there is an ace-5 flush
                        condensedCards[1] = 3;
                    }
                }
            }
        }
        if (hasQuality[1] && hasQuality[0]) {
            condensedCards[0] = 8;
            return condensedCards;
        }
        if (hasQuality[1] && !hasQuality[0]) {
            condensedCards[0] = 4;
            return condensedCards;
        }
        if (hasQuality[0] && !hasQuality[1]) {
            condensedCards[0] = 5;
            for(i=2;i<=5;i++){
                condensedCards[i]=straightCards[i-1];
            }
            return condensedCards;
        }
        card = 0;

        for (i = 0; i < lookForPairsHere.length; i++) {
            numberOfEachValuedCard[lookForPairsHere[i]]++;
        }
        for (i = 12; i >= 0 && card < 5; i--) {
            // create an array that has how much of each card
            if (numberOfEachValuedCard[i] > 0) {
                pairs[2 * card] = numberOfEachValuedCard[i];
                pairs[2 * card + 1] = i;
                card++;
            }
        }

//parse the array above
        int[] pairCondensed = {0, 0, 0, 0, 0};
        for (i = 0; i < 5; i++) {
            pairCondensed[i] = pairs[2 * i];
        }
        //highest to lowest
        Arrays.sort(pairCondensed);
        pairCondensed = reverse(pairCondensed);

        if (pairCondensed[0] == 4 && pairCondensed[1] == 1) {
            //four of a kind
            condensedCards[0] = 7;
            for (i = 0; pairs[i] > 0; i += 2) {
                if (pairs[i] == 4) {
                    condensedCards[1] = pairs[i + 1];
                }
                for (j = 0; j < 10; j += 2) {
                    if (pairs[j] == 1) {
                        condensedCards[2] = pairs[j + 1];
                        break;
                    }
                }
            }
            return condensedCards;
        }
        if (pairCondensed[0] == 3 && pairCondensed[1] == 2) {
            //full house
            condensedCards[0] = 6;
            for (i = 0; i < 10; i += 2) {
                if (pairs[i] == 3) {
                    condensedCards[1] = pairs[i + 1];
                }
                if (pairs[i] == 2) {
                    condensedCards[2] = pairs[i + 1];
                }
            }
            return condensedCards;
        }
        if (pairCondensed[0] == 3 && pairCondensed[1] == 1) {
            //three kind
            condensedCards[0] = 3;
            for (i = 0; i < 10; i += 2) {
                if (pairs[i] == 3) {
                    condensedCards[1] = pairs[i + 1];
                }
            }

            //kicker stuff here
            j = 3;
            for (i = 0; j < 5; i++) {
                if (unsuitedCards[i] != condensedCards[1]) {
                    condensedCards[j] = unsuitedCards[i];
                    j++;
                }
            }
        }
        if (pairCondensed[0] == 2 && pairCondensed[1] == 2) {

//two pair
            condensedCards[0] = 2;
            for (i = 0; i < 10; i += 2) {
                if (pairs[i] == 2 && condensedCards[1] == -1) {
                    condensedCards[1] = pairs[i + 1];
                }
                if (pairs[i] == 2 && condensedCards[1] != -1) {
                    condensedCards[2] = pairs[i + 1];
                }
            }
            if (condensedCards[2] > condensedCards[1]) {
                int temp2 = condensedCards[2];
                int temp1 = condensedCards[1];
                condensedCards[1] = temp2;
                condensedCards[2] = temp1;
            }

            //kicker stuff here
            j = 3;
            for (i = 0; j < 4; i++) {
                if (unsuitedCards[i]
                        != condensedCards[1] && unsuitedCards[i]
                        != condensedCards[2]) {
                    condensedCards[j] = unsuitedCards[i];
                    j++;
                }
            }
        }
        if (pairCondensed[0] == 2&&pairCondensed[1]==1) {
            //one pair
            condensedCards[0] = 1;
            for (i = 0; i < 10; i += 2) {

                if (pairs[i] == 2) {
                    condensedCards[1] = pairs[i + 1];
                }
            }
            //kicker stuff here
            j = 3;
            for (i = 0; j < 6 && i < 5; i++) {
                if (unsuitedCards[i] != condensedCards[1]) {
                    condensedCards[j] = unsuitedCards[i];
                    j++;
                }
            }
        }

        if (condensedCards[0] == 0) {
            //high card/ no pair
            for (i = 0,j=1; j <=5 && i < originalCards.length; i++) {
condensedCards[j]=lookForPairsHere[i];
                j++;
            }
        }

        return condensedCards;
    }