Problem with random shuffle

[garanon]

I used to be using a vector as my card pack which would use a random shuffle function fine, but I recently changed it to an array which has brought up a few problems for me

#include algorithm
void Deck::Shuffle()
{	
	srand(time(0));
	random_shuffle(s_CardPack[0][0], s_CardPack[51][0]);
}

when I try to compile it opens up #algorithm and highlights line 63, I'm not sure why.
Did I write it wrong?

Also, I want to make sure that, for example, if [2][0] was shuffled to [30][0], that [2][1] would also be moved to [30][1].

Is this possible with the random shuffle function or do I have to code a for loop myself?

[Disch]

- It's #include <algorithm> . Don't forget the <angle brackets>.

- Can't tell you if you're calling random_shuffle incorrectly without knowing what s_CardPack is. Can you show us how that is defined?

and highlights line 63

Which line is line 63? I only see 6 lines.

Also, I want to make sure that, for example, if [2][0] was shuffled to [30][0], that [2][1] would also be moved to [30][1].
Is this possible with the random shuffle function or do I have to code a for loop myself?

You should not try to keep multiple different arrays in sync. If you have lots of different information that needs to stay together, put it in a struct, then have an array of that struct:

struct Card
{
  int suit;
  int rank;
};

Card deck[52];

 // initialize your deck here

random_shuffle(deck, deck + 52);

[garanon]

Oops i did include brackets I just typed that really fast before I pressed enter to avoid getting responses saying that was my problem :P So much for that

static string s_CardPack[52][3]; <-- thats how I defined s_CardPack

When I said it highlights line 63, I meant in the algorithm include file:
#include <bits/stl_algo.h>
that is highlighted with no error to tell me what I am doing wrong.


Anyway I haven't heard of a struct before but it looks like it could save me a lot of time. So does your example mean that creating deck[52] will be a single object and suit and rank will also be arrays? or are you creating 52 different deck "structs" each with their own individual suit and rank?

[Disch]

When I said it highlights line 63, I meant in the algorithm include file:
#include <bits/stl_algo.h>

I don't know what header that is... but the header that has random_shuffle in it is this:

#include <algorithm> 

So I would erase what you have there and replace it with that.

or are you creating 52 different deck "structs" each with their own individual suit and rank?

This.

Card deck[52];

deck[0].suit = /*spade*/;
deck[0].rank = /*Ace*/

[viliml]

You need to learn a LOT about iterators.
1. Random_shuffle() accepts iterators as inputs.
2. Vector::begin() and end() return iterators.
3. Iterators are basicly pointers
1.+2.+3. Don't dereference the begin and end of your array when using them as iterators!!!
Use this:

#include <algorithm>
void Deck::Shuffle()
{	
	srand(time(0));
	random_shuffle(s_CardPack[0], s_CardPack[51]+3);
}

PS: Why do you even have 2 dimensions in your array???

[viliml]

BTW Disch, bits/stl_algo.h is where the actual functions are defined. Algorithm is there just to include some extra needed headers and for the name to be simpler

[garanon]

Awesome, thanks Disch for the info on structs. Looks a lot easier and cleaner to work with

@viliml
I had two dimensions in my array because I hadn't used structs before, and I want more than just a simple "A\3" for my card. I want to be able to compare them with other cards, which is why I had the other dimension to store an integer value and suit in it as well as the face appearance. Now that I know about structs though it looks like I can just use that

Also thanks for the info on iterators. The book never explained why arrays were made into iterators but not vectors, but now I know :P