array of struct by reference ** RESOLVED!!!**

[ae_jester]

Hi,

I need help setting up the prototype, the actual function header, and the code used to modify the structure being sent to the function. I need to pass the array of this structure by reference so that any changes made change the original data sent in.

THis is what I have so far.

'My prototype
int getlegalmoves(struct postype pos, struct movetype *movelist[]);
 
'The function code
int getlegalmoves(struct postype pos, struct movetype *movelist[])
{
    movelist[0].from = 1;
    movelist[0].to = 2;
    movelist[1].from = 3;
    movelist[1].to = 4;
}

[NoteMe]

I am sooo not good at this....but if you to pass it as a reference...why are you using * and not &???


And BTW isn't movelist[] just a pointer to that array. So you are actually all ready changing the originale.....ro am I wrong?

[ae_jester]

I am sooo not good at this....

I am worse, which is why I am asking. I'm trying to convert a vb program to c++ and its becoming a nightmare!

[NoteMe]

I am pretty sure it is a pointer....so you don't need the ? in front of it...that will just make it a pointer to a pointer...and if you have a pointer you are maybe copying the pointer....but that is no work at all. But you are still working on the same struckt as before using that pointer....Thats at least what I would have written on my exam........hehe

[ae_jester]

Ok, I changed it to the following, but I still get an error (same one) on the line where I'm calling this function ("local function definitions are illegal")...here is all the relevant code...

struct postype
{
    int blacks;
    int whites;
    int kings;
    int colour;
    int hashval;
}game;
 
struct movetype
{
    int blacks;
    int whites;
    int kings;
    short from;
    short to;
};
 
'prototypes
int getlegalmoves(struct postype pos, struct movetype movelist[20]);
int alphabeta(struct postype pos, int depth, int alpha, int beta);
 
int alphabeta(struct postype pos, int depth, int alpha, int beta)
{
    struct movetype movelist[20];
    int i, j, n, value, localalpha, bestvalue, hashvalue, hashtype, lookupvalue;
    struct postype localpos;
    short sqrfrom, sqrto;
    
    bestvalue = -1000;
    localpos = pos;
    localalpha = alpha;
    
    if (depth==0)
    {
        value=evaluation(pos);
        return value;
    }
    
    //n = getlegaljumps(pos, movelist);
    if (n==0)
    {
        n = getlegalmoves(pos, movelist); '<-- ERROR OCCURS HERE
    }
 
    for(i=0; i<n; i++)
    {
        pos.blacks = movelist[i].blacks;
        pos.whites = movelist[i].whites;
        pos.kings = movelist[i].kings;
        pos.colour = abs(pos.colour - 3);
                
        value = -alphabeta(pos, depth-1, -beta, -localalpha);
 
        pos = localpos;
 
        bestvalue = max(value, bestvalue);
 
        if (bestvalue>=beta)
        {
            break;
        }
 
        if (bestvalue>localalpha)
        {
            localalpha = bestvalue;
        }
    }
    
    return bestvalue;
}
 
 
 
 
 
 
int getlegalmoves(struct postype pos, struct movetype movelist[20])
{
    int i, j;
    int totalmoves;
    int sqrfrom, sqrto;
 
    totalmoves=0;
 
    if(pos.colour == BLACK)
    {
        for(i=0;i<32;i++)
        {
            sqrfrom=i;
            if((pos.blacks & i) && !(pos.kings & i))
            {
                for(j=0; j<movecounts[bp][sqrfrom]; j++)
                {
                    sqrto = legalmoves[bp][sqrfrom][j];
                    if (!(pos.blacks & sqrto) && !(pos.whites & sqrto))
                    {
                        // This is a valid move
                        movelist[totalmoves].blacks = pos.blacks;
                        movelist[totalmoves].whites = pos.whites;
                        movelist[totalmoves].kings = pos.kings;
                        movelist[totalmoves].from = sqrfrom;
                        movelist[totalmoves].to = sqrto;
                        
                        totalmoves++;
                    }
                }
            }
        }
    }
    return totalmoves;
}

[NoteMe]

Why do you have 20 in the parameter list of your function? Try just [], not [20]

[ae_jester]

I'm getting the same error with or without them in there.

I'm also starting to think that something else 'might' be causing all this crap to happen........argh now i know why i hate c++

[ae_jester]

I'm attaching my cpp file in case anyone has time to look at it. Maybe you can see something I don't.

Thanks

[NoteMe]

What compiler are you using....never seen stdafx.h before....is that anything you made?

[NoteMe]

I searched my computer and found about 20 files called that...most of them in the DX8 SDK and one in mfc/src and one in atl/src


Do you know what you are using?

[NoteMe]

Hehe...now I am having problems here....those folders are added to the directory list so the compiler should have no problem of finding them....stupid C++...

[NoteMe]

Hehehe...I moved the protoyupe at the top of the prototypes, and the function over the last one...and then everything worked.......no idea why tho'.....

[NoteMe]

Or actually I still get the

C:\struct.cpp(468) : fatal error C1004: unexpected end of file found

error....not sure what is causing that but I commented out the #include "STDAFX.H" becuase I have no idea why C++ could not find it...and I have no idea what you are using it for...so that may couase that error...I don't know...

[NoteMe]

And you have to initialise n in the alphabeta function....and ther is some error in the evaluation function...can't see the problem...looks like you have missed out a } but I can't find where....and it sais that not all paths have a return value....

[NoteMe]

FOUND IT....your BIG problem was that the evaluation function has two {{ in the last if test....so try to take away one of them and initialise n then you are ready to rumble....just ignore all other posts from me...


[Edit]Now I have deserved the date I am on my way too....hitting the shower...happy C++ programming[/Edit]

[ae_jester]

Ahhhhh

I knew it would be something so stupid

Thanks so much!

[ae_jester]

I'm using Microsoft Visual C++ 6.0

STDAFX.H was automatically included when I started a new project. I have no idea why either.

[NoteMe]

Originally posted by ae_jester
Ahhhhh

I knew it would be something so stupid

Thanks so much!

Your subject still says unresolved......was there something more you wondered about...??

[NoteMe]

Originally posted by ae_jester
I'm using Microsoft Visual C++ 6.0

STDAFX.H was automatically included when I started a new project. I have no idea why either.

I am always starting with a clean project...so nothing else then what I want is added....but if you want it there no worries....even if I can't see whee you are using anything from it...

[ae_jester]

NoteMe, do u know of any good forums for c++? This one is kinda 'slow' if you ask me.

[NoteMe]

Hehe...wasn't I fast enough.......no sorry....I havn't had time to look yet....I have only been doing C++ for 4 months....so this was more or less the first non school C++ app I have ever seen...

[CornedBee]

cboard.cprogramming.com is very good.

Kinda loaded server though.

[NoteMe]

Thanks will check it out after X-Mas