Java: Poker Hand

Question

So, I have to create a poker hand program using functions/methods and arrays.

Here's a sample output I need to have:

Enter five numeric cards, no face cards. Use 2 - 9.Card 1: 8 

Card 2: 7
Card 3: 8
Card 4: 2
Card 5: 7
Two Pair!

Enter five numeric cards, no face cards. Use 2 - 9.
Card 1: 4 
Card 2: 5
Card 3: 6
Card 4: 8
Card 5: 7
Straight!

Enter five numeric cards, no face cards. Use 2 - 9.
Card 1: 9
Card 2: 2
Card 3: 3
Card 4: 4
Card 5: 5
High Card!

And here's my code (I'm having issues with logic in determining if one gets pair, 3 of a kind, etc.). They have be methods/functions. So, if I can figure out how to do 1 or 2 of them, it should be hopefully be a breeze from there:

import java.util.Scanner;

public class Assignment4 
{
    public static void main(String args[])
    {
        final int LEN = 5;
        int[] hand = new int[LEN];

    Scanner input = new Scanner(System.in);

    //input the hand
    System.out.println("Enter five numeric cards, no face cards. Use 2-9.");
    for (int index = 0; index < hand.length; index++) {
        System.out.print("Card " + (index + 1) + ": ");
        hand[index] = input.nextInt();
    }

    //sort the collection
    bubbleSortCards(hand);

    //determine players hand type
    //flow of evaluation -> checking complex hands first  
    if (containsFullHouse(hand)) {
        System.out.println("Full House!");
    } else if (containsStraight(hand)) {
        System.out.println("Straight!");
    } else if (containsFourOfaKind(hand)) {
        System.out.println("Four of a Kind!");
    } else if (containsThreeOfaKind(hand)) {
        System.out.println("Three of a Kind!");
    } else if (containsTwoPair(hand)) {
        System.out.println("Two Pair!");
    } else if (containsPair(hand)) {
        System.out.println("Pair!");
    } else 
        System.out.println("High Card!");   
}

And this is the recommended way from the assignment's instructions:

public class PokerHand
{
    public static void main(String args[])
    {
        int hand[] = {5, 2, 2, 3, 8};

        if (containsAPair(hand)) {
                System.out.println("Pair!");
        } else {
                System.out.println("Not a pair!");
        }
}

public static boolean containsAPair(int hand[]) {
        // Your code here... don’t return true every time...
        return true;
}

}

If more information is needed, I'll be more than happy to supply that. THANKS!

Answer 1

Instead of sorting the hand, I would recommend that you tally the contents of a hand and generate an array of counts, where the i ^th element of the array has the number of cards with value i . You should then be able to figure out how to use that array to decide whether it is a particular type of hand.

Answer 2

Since this is homework, I'll point you in a direction to get started to help you think about a solution.

In your post, you need to create the code for the containsFullHouse() , containsStraight() and so on. So...

• Grab a deck of cards. Remove the face cards and aces.
• Imagine you're playing poker. Give yourself a hand that's a four of a kind. Think about how you, as a person, would determine what you have. I would personally sort my hand, then count the incidences of each card. If I have 4 of the same value, then I've got a four of a kind and can stop.
• Okay, now a straight. I'd again sort my hand. If every card c has c + 1 as the next card's value, except the last, I have a straight.
• Repeat this process until you work down to the lowest valued hands.