Shuffling a deck of cards

[Jinz0]

Hi all,

im working on a simple deck of cards project and i've got to the shuffle bit and hit a brick wall. Im not sure how i am meant to do this as our tutor has instructed us to use pointers to pointers like this e.g.
PlayingCard**_playing_cards;

i have my build deck function which works just fine and it is..

void Deck::build_deck()
{

    for( int suit = 1; suit <= 4 && _deal_next != 51; suit++ && _deal_next+13)
        {
            for( int fvalue = 1; fvalue <= 13; fvalue++ )
                {
                    _playing_cards[_deal_next] = new PlayingCard( fvalue, suit );
                   /* cout << PlayingCard( fvalue, suit ) << endl; */
                }
           
        }

}

Then this is what i have so far for the shuffle function..

void Deck::shuffle_deck()
{

 for( int i = 0; i < 52; i++)
 {
      int random_card01 = rand() % 52;
               
      _playing_cards[random_card01]*
 }
     
}

Thanks in advance for any help you can give, and i dont mind being told stuff is wrong haha :).

[Peter87]

I doubt build_deck is working correctly. _deal_next doesn't change anywhere so only one element in the array will be set. Why not start _deal_next as zero and increment it in the inner loop ++_deal_next;?

You can use std::random_shuffle to shuffle the deck.
std::random_shuffle(_playing_cards, _playing_cards + 52);

[Jinz0]

Sorry, I have set _deal_next = 0 as default in the class constructor so it works, I tested it :). And thanks for the shuffle bit :)!

[clanmjc]

Jinz, I think what Peter was saying is that _deal_next never gets assigned a new value. _deal_next + 13 does this...

0 + 13, there is no assignment. Every time you loop through a suit, you will be indexing into your array with 13. I'm not sure how it works (I guess there is code that is not posted?)

[Jinz0]

(I guess there is code that is not posted?)

Yes there is code that isn't posted clanmjc here's my whole deck.cpp file :)

#include "deck01.hpp"
#include <cstdlib>
#include <ctime>
#include <iostream>

using namespace std;



Deck::Deck( int total_cards )
{
    _total_playing_cards = total_cards;

    _playing_cards = new PlayingCard*[total_cards];

    _deal_next = 0;
}

void Deck::build_deck()
{
     
for( int suit = 1; suit <= 4 && _deal_next != 51; ++suit, _deal_next+13)
        {
            for( int fvalue = 1; fvalue <= 13; fvalue++ && _deal_next++)
                {
                    _playing_cards[_deal_next] = new PlayingCard( fvalue, suit );
                    
                    cout << PlayingCard( fvalue, suit ) << endl;
                    
                    
                }
           
        }
/*    for( int suit = 1; suit <= 4 && _deal_next != 51; suit++)
        {
            for( int fvalue = 1; fvalue <= 13; fvalue++ && _deal_next++)
                {
                    _playing_cards[_deal_next] = new PlayingCard( fvalue, suit );
                    cout << PlayingCard( fvalue, suit ) << endl;
                    
                }
           
        }

*/
}

void Deck::shuffle_deck()
{

std::random_shuffle(_playing_cards, _playing_cards + 52);
     
}

PlayingCard Deck::deal_card()
{


 
}

/*void PictureDeck::build_deck()
{

    for( int suit = 1; suit <= 4 && _deal_next != 51; suit++ && _deal_next+13)
        {
            for( int fvalue = 1; fvalue <= 13; fvalue+10 )
                {
                    _playing_cards[_deal_next] = new PlayingCard( fvalue, suit );
                    cout << PlayingCard( fvalue, suit ) << endl;
                }
           
        }

}

*/

/* to shuffle...
pick one random card store it in a tempory spot..
select another random card..
put the second card into the first spot..
put the first card into the second spot..
repeat 60 times.. */

I hope that clears some things up :)

[clanmjc]

I hope that clears some things up :)

It certainly does! You good to go looks like your shuffling now?