a really large allocation

[FzzPoofy]

Hi, I'm having an issue with an allocation error. I have a very large integer nwk that is an unsigned long.

I want to dynamically allocate an array of length nwk

double *A = new double[nwk+1];

but I am getting this error:

terminate called after throwing an instance of 'std::bad_alloc'
what(): St9bad_alloc

I assume this is because I'm trying to allocate a really long array. But I need all that space to solve this large problem. Is there some way to fix this?

[zb0S216C]

You could try implementing a linked-list, where each node is a block of allocated memory:

struct LinkedList
{
    struct Node 
    {
        Node(unsigned int const size = 0u);
       ~Node();

        double *memory;
    };

    LinkedList(unsigned int const node_count = 0u);
   ~LinkedList();

    private:
        Node *next;

    public:
        // Interface...
};

I would suggest a standard container, but I don't know if they are suitable.

_Wazzak

[o3hC5Di1]

Hi there,

It's hard to tell without knowing the size of nwk.
If I remember correctly, double's are 8 bytes large, so multiply that by nwk and you'll have an idea of how much memory you're trying to allocate.

Perhaps an STL container (vector, deque,...) would also be a safer way to implement such large storage.

All the best,
NwN

[ne555]

But I need all that space to solve this large problem.

¿are you sure?

[zb0S216C]

@ne555: No, (s)he wants to allocate a large block of memory for kicks. If they need the memory, so be it; there's no need to question their requirements. Besides, we don't even know what the program is or even does.

Wazzak

[ne555]

That's exactly what I'm trying to know (in order to provide an useful answer)

If you run out of memory then download some RAM, xP