Example: High-Performance Card Shuffling and Dealing Simulation

Example High Performance Card Shuffling and Dealing Simulation

The program in Figs. 22.222.4 is based on the card shuffling and dealing simulation discussed in Chapter 8. The program represents the deck of cards as an array of structures and uses high-performance shuffling and dealing algorithms.

Figure 22.2. Header file for DeckOfCards class.

 1 // Fig. 22.2: DeckOfCards.h
 2 // Definition of class DeckOfCards that
 3 // represents a deck of playing cards.
 4
 5 // Card structure definition
 6 struct Card 
 7 { 
 8  char *face; 
 9  char *suit; 
10 }; // end structure Card 
11
12 // DeckOfCards class definition
13 class DeckOfCards
14 {
15 public:
16 DeckOfCards(); // constructor initializes deck
17 void shuffle(); // shuffles cards in deck
18 void deal(); // deals cards in deck
19
20 private:
21 Card deck[ 52 ]; // represents deck of cards
22 }; // end class DeckOfCards

Figure 22.3. Class file for DeckOfCards.

(This item is displayed on pages 1062 - 1064 in the print version)

 1 // Fig. 22.3: DeckOfCards.cpp
 2 // Member-function definitions for class DeckOfCards that simulates
 3 // the shuffling and dealing of a deck of playing cards.
 4 #include 
 5 using std::cout;
 6 using std::left;
 7 using std::right;
 8
 9 #include 
10 using std::setw;
11
12 #include  // prototypes for rand and srand
13 using std::rand;
14 using std::srand;
15
16 #include  // prototype for time
17 using std::time;
18
19 #include "DeckOfCards.h" // DeckOfCards class definition
20
21 // no-argument DeckOfCards constructor intializes deck
22 DeckOfCards::DeckOfCards()
23 {
24 // initialize suit array
25 static char *suit[ 4 ] =
26 { "Hearts", "Diamonds", "Clubs", "Spades" };
27
28 // initialize face array
29 static char *face[ 13 ] =
30 { "Ace", "Deuce", "Three", "Four", "Five", "Six", "Seven",
31 "Eight", "Nine", "Ten", "Jack", "Queen", "King" };
32
33 // set values for deck of 52 Cards
34 for ( int i = 0; i < 52; i++ )
35 {
36 deck[ i ].face = face[ i % 13 ];
37 deck[ i ].suit = suit[ i / 13 ];
38 } // end for
39
40 srand( time( 0 ) ); // seed random number generator
41 } // end no-argument DeckOfCards constructor
42
43 // shuffle cards in deck
44 void DeckOfCards::shuffle()
45 {
46 // shuffle cards randomly
47 for ( int i = 0; i < 52; i++ )
48 {
49 int j = rand() % 52;
50 Card temp = deck[ i ];
51 deck[ i ] = deck[ j ];
52 deck[ j ] = temp; 
53 } // end for
54 } // end function shuffle
55
56 // deal cards in deck
57 void DeckOfCards::deal()
58 {
59 // display each card's face and suit
60 for ( int i = 0; i < 52; i++ )
61 cout << right << setw( 5 ) << deck[ i ].face << " of "
62 << left << setw( 8 ) << deck[ i ].suit
63 << ( ( i + 1 ) % 2 ? '	' : '
' );
64 } // end function deal

---

Figure 22.4. High-performance card shuffling and dealing simulation.

 1 // Fig. 22.4: fig22_04.cpp
 2 // Card shuffling and dealing program.
 3 #include "DeckOfCards.h" // DeckOfCards class definition
 4
 5 int main()
 6 {
 7 DeckOfCards deckOfCards; // create DeckOfCards object
 8
 9 deckOfCards.shuffle(); // shuffle the cards in the deck
10 deckOfCards.deal(); // deal the cards in the deck
11 return 0; // indicates successful termination
12 } // end main

 

 King of Clubs Ten of Diamonds
 Five of Diamonds Jack of Clubs
 Seven of Spades Five of Clubs
 Three of Spades King of Hearts
 Ten of Clubs Eight of Spades
 Eight of Hearts Six of Hearts
 Nine of Diamonds Nine of Clubs
 Three of Diamonds Queen of Hearts
 Six of Clubs Seven of Hearts
 Seven of Diamonds Jack of Diamonds
 Jack of Spades King of Diamonds
 Deuce of Diamonds Four of Clubs
 Three of Clubs Five of Hearts
 Eight of Clubs Ace of Hearts
 Deuce of Spades Ace of Clubs
 Ten of Spades Eight of Diamonds
 Ten of Hearts Six of Spades
 Queen of Diamonds Nine of Hearts
 Seven of Clubs Queen of Clubs
 Deuce of Clubs Queen of Spades
 Three of Hearts Five of Spades
 Deuce of Hearts Jack of Hearts
 Four of Hearts Ace of Diamonds
 Nine of Spades Four of Diamonds
 Ace of Spades Six of Diamonds
 Four of Spades King of Spades

 

In the program, the constructor initializes the Card array in order with character strings representing the Ace through the King of each suit. Function shuffle is where the high-performance shuffling algorithm is implemented. The function loops through all 52 cards (array subscripts 0 to 51). For each card, a number between 0 and 51 is picked randomly. Next, the current Card structure and the randomly selected Card structure are swapped in the array. A total of 52 swaps are made in a single pass of the entire array, and the array of Card structures is shuffled! Unlike the shuffling algorithm presented in Chapter 8, this algorithm does not suffer from indefinite postponement. Because the Card structures were swapped in place in the array, the high-performance dealing algorithm implemented in function deal requires only one pass of the array to deal the shuffled cards.

---