Poker Hand

1
Poker Hand

• Project 6
• Mon, Dec 1, 2003
• Due Mon, Dec 8, 2003

2
The PokerHand Program

• This program will
• Generate a specified number of poker hands at
  random.
• Categorize each hand.
• Report
• The number of hands in each category.
• The relative frequency of each category.

3
The Card Class

• Each card has a suit and a face value.
• Suit is an enumerated type.
• enum Suit clubs, diamonds, hearts, spades
• Face is an enumerated type.
• enum Face two, three, four, five, six, seven,
  eight, nine, ten, jack, queen, king, ace

4
The Order Relation on Cards

• The function operatorlt() is defined to compare
  Cards
• First by Face value,
• Then by Suit.
• For example,
• two of spades lt ace of clubs
• The two of clubs is the lowest Card.
• The ace of spades is the highest Card.

5
The Deck Class

• A Deck object consists of
• An array of 52 Cards.
• A RandomInt object, used to shuffle the deck.

6
The Deck Class

• Internally, in the array, the cards are indexed
  as 0 through 51.
• Externally, through the user interface, they are
  indexed as 1 through 52.

Card DeckgetCard(int i) const assert(i gt 1
i lt 52) return cardsi - 1
7
The PokerHand Class

• A PokerHand object consists of an array of 5
  Cards.
• The quality of a hand is the type of poker hand
  that it is.
• enum Quality nothing, onePair, twoPairs,
  threeOfAKind, straight, aFlush, fullHouse,
  fourOfAKind, straightFlush, royalFlush

8
The Deck Class (again)

• The Deal() function returns a PokerHand object,
  consisting of 5 Cards dealt from the top of the
  deck.
• This function should get cards 1 5 from the
  deck and set them in the poker hand.

9
Determining the Type of Hand

• To facilitate the analysis of the hand, many of
  the functions should first arrange the cards in
  order.
• That makes it much easier to check for one pair,
  two pairs, three of a kind, four of a kind, etc.
• Use a Sort() function to do this.

10
The sort() Function

• Use any of the sorting algorithms that we
  discussed.
• When swapping cards, either
• Swap the array elements, or
• Use GetCard() and SetCard() to move them.
• The order imposed on the cards is the order
  defined by operatorlt() in the Card class.

11
The hasOnePair() Function
bool PokerHandhasOnePair() const
PokerHand hand copyHand() hand.sort()
CardFace f1 hand.getCard(1).getFace()
CardFace f2 hand.getCard(2).getFace()
CardFace f3 hand.getCard(3).getFace()
CardFace f4 hand.getCard(4).getFace()
CardFace f5 hand.getCard(5).getFace()
return (f1 f2) (f2 f3) (f3
f4) (f4 f5)
12
Determining the Quality of the Hand

• Once the hand is sorted, two pairs can occur in
  only 3 ways.
• The possible patterns are
• AABBC
• AABCC
• ABBCC
• How many patterns were possible before the hand
  was sorted?

13
Determining the Quality of the Hand

• In a sorted hand, what are the possible patterns
  for
• Three of a kind?
• Four of a kind?
• A full house?

14
Determining the Quality of the Hand

• Test for a flush by seeing if all the cards have
  the same suit.
• Test for a straight by seeing if each card has a
  value one greater than the card before it.
• A straight flush is both a straight and a flush.
• Call hasStraight() and hasFlush().

15
Determining the Quality of the Hand

• A royal flush is a straight flush in which the
  high card is an ace.
• Call hasStraightFlush() and getHighCard().

16
Determining the Quality of the Hand

• The quality() function must test for the simpler
  types first. Otherwise, the function may
  miscategorize the hand.
• For example, if a hand has four of a kind, then
  the functions hasThreeOfAKind(), hasOnePair(),
  and hasTwoPairs() will also return true.

17
The main() Function

• The main() function should generate at random the
  specified number of PokerHands.
• Shuffle the deck every time before dealing a
  hand.
• Each hand should be categorized according to its
  quality.
• A counter for that type of hand should be
  incremented.
• Print the counts and the relative frequencies.

18
The Output

• The output will be different every time the
  program is run, even for the same input.
• However, the following chart shows what to expect.