Large Size Array 1

[mirok]

Hi,

I got a problem in VC++. I am trying to run the following program with VC++ but it terminates. The problem is with the size of array. If I change the arraydimension to 50 everything works prefectry but I need to work with large array size. If you have any information regarding this case please let me know.

Thanks

#include <iostream>
using namespace std;
int main()
{

int n=0;
int p=0;
int k=0;
int l=0;
const dimensionarray=60;
int count[dimensionarray][dimensionarray][dimensionarray][2];
for (n=1; n<dimensionarray; n++)
{
for (p=1; p<dimensionarray; p++)
{
for (k=1; k<dimensionarray; k++)
{
for (l=1; l<2; l++)
{
count[n][p][k][l]=n+p+k+l;
printf("%d",count[n][p][k][l]);
}
}
}
}
cout << "Thanks for Helping me";
return 0;
}

 

[MacGyverS2000]

That's a mighty big array. I don't know what, if any, limits VC++ sets on build-time arrays, but you may want to try making it a run-time array (i.e., allocate/deallocate memory using new()/delete() ).

 

[CajunCenturion]

I think you're dealing with memory issues. A 60 x 60 x 60 x 2 dimension array (assuming 4 byte integers) is over 1.7 Mb and finding that much heap space could prove problematic, especially if the array implementation requires contiguous memory. You might want to consider using a temporary table in a DB for your storage.

 

[mirok]

Hi MacGyverS2000,

Thanks for your helpful hint. I was successful in allocating a one dimensional array with a very large size. The only problem I have now is to be able to allocate a
4 dimesional array. Would you please help me agian if you have any idea regarding this case.

Thanks again.

 

[MacGyverS2000]

If the array truly needs to be 4D, you may want to consider making a 4D array of pointers to make access easier. This is a 1D array of pointers. Each of those array elements points to the start of another set of arrays, also pointers. Do this a few times and you have a nice 4D array, that can be accessed quite easily.

Since the computer is going to view all of this as pointer arithmetic anyway, you're going to see a nice speed increase compared to what you're currently running.