From:	"News Reader" <nospam AT aol DOT com>
Newsgroups:	comp.os.msdos.djgpp
Subject:	Re: Newbie: multidimensional arrays problem
Date:	Thu, 28 Aug 2003 21:15:27 +0200
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You can leave your arrays inside the main() function as long as
they are declared static. The following is an example of your
program adapted to C (C++ could be arranged accordingly):


int main (int argc, char **argv)
{
  int x,y;
  puts(" currently here\n");  // you won't need this anymore   ; )

  #define Xmax 1200  // 'const int' does not work with static arrays
  #define Tmax 51

  static double price[Tmax][Xmax+1];
  static double reslevel[Tmax][Xmax+1];

// lots of code that doesn't involve price or reslevel

// I am just doing something with the arrays here,  because ...
// ... the optimizer might not generate any code otherwise:

  for (x=0; x<=Xmax; x++) for (y=0; y<Tmax; y++) {
    price[y][x]=x+y; reslevel[y][x]=x-y;
  }
  for (n=0,x=0; x<=Xmax; x++) for (y=0; y<Tmax; y++) {
    n+=price[y][x]-reslevel[y][x];
  }
  printf("\nn:%d\n\n",n);
  return 0;
}

Remark: static arrays are not using any stack space, therefore
the program should work without problems.


"Tom Weston" <tomweston_usenet AT yahoo DOT com> wrote in message
news:87752c88 DOT 0308270034 DOT 646465b AT posting DOT google DOT com...
> I'm quite a novice with c++ so this is probably more a language
> issue than a compiler/system one but I've been writing a program
> and have just included some multidimensional arrays that make
> for a strange effect that I can't explain.
>
> As the program currently stands it looks i outline like this
>
> int main()
> {
>
> cout << " currently here\n";
>
> const int xmax=1200;
> const int tmax=51;
>
> double price[tmax][xmax+1];
> double reslevel[tmax][xmax+1];
>
> // lots of code that doesn't involve price or reslevel
>
> return 0;
>
> }
>
> This compiles and when run doesn't print anything.
> If I comment out the two lines dimensioning the multi-dim
> arrays, it compiles and runs fine.
> If I change the data type of the arrays to int or float,
> it compiles OK and runs fine.
>
> This seems a bit bizarre to me, but as I say, I'm not experienced
> with C++.
>
> Any ideas?
>
> Many thanks,
> Tom

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