PokerHand.java

/******************************************************************************
  * name: Donna Gabai
  * netID: dgabai
  * precept: P99
  * 
  * Description: 
  * PokerHand data type.
  * Can construct a hand from standard input, format a hand for output,
  * determine if a hand is a flush or a full house.
  * Test main() sets up 5-card poker hands from standard input,
  * prints flushes and full houses (one per line).
  * 
  * Dependencies: StdIn, StdOut
  */

public class PokerHand {
    // class constants
    private static final int HANDSIZE = 5;  // 5 cards per hand
    
    // instance variables
    private String[] hand;                  // each String is one card
    
    // constructor reads a 5-card poker hand from StdIn
    public PokerHand() {
        hand = new String[HANDSIZE];
        for (int i = 0; i < HANDSIZE; i++) {
            hand[i] = StdIn.readString();
        }
        
        // sort the hand, note Queen is higher than King!
        // Ten is highest of all!
        // 2, 3, 4, 5, 6, 7, 8, 9, A, J, K, Q, T
        java.util.Arrays.sort(hand);
        
    }
    
    // is this hand a flush?
    public boolean flush() {
        // looking for suit (last character) all the same
        char suit = hand[0].charAt(1);
        for (int i = 1; i < HANDSIZE; i++) {
            if (suit != hand[i].charAt(1)) return false;
        }
        // made it through!  ALL EQUAL!
        return true;
    }
    
    // is this hand a full house?
    public boolean fullHouse() {
        // looking for 3 matching and 2 matching
        // since hand is sorted, first and last will be different
        // first card
        char rank1 = hand[0].charAt(0);
        int sumRank1 = 1;
        // last card
        char rank2 = hand[HANDSIZE - 1].charAt(0);
        int sumRank2 = 1;
        // count cards similar to first and last cards
        for (int i = 1; i < HANDSIZE - 1; i++) {
            if (hand[i].charAt(0) == rank1) sumRank1++;
            if (hand[i].charAt(0) == rank2) sumRank2++;
        }

        // is it a full house?
        if (sumRank1 == 3 && sumRank2 == 2) return true;
        if (sumRank1 == 2 && sumRank2 == 3) return true;
        // no full house :(
        return false;
    }
    
    // string representation of this hand sorted
    public String toString() {
        String wholeHand = "";
        for (int i = 0; i < HANDSIZE; i++)
            wholeHand = wholeHand + hand[i] + " ";
        return wholeHand;
    }
    
    // test main
    public static void main(String[] args) {
        // input one hand at a time
        // output it if it is a flush or full house
        while (!StdIn.isEmpty()) {
            PokerHand ph = new PokerHand();
            if (ph.flush()) StdOut.println("     Flush: " + ph);
            if (ph.fullHouse()) StdOut.println("Full house: " + ph);
        }
    }
}