Getting a stack overflow exception when declaring a large array

Question

The following code is generating a stack overflow error for me

int main(int argc, char* argv[]) {     int sieve[2000000];     return 0; } 

How do I get around this? I am using Turbo C++ but would like to keep my code in C

EDIT:

Thanks for the advice. The code above was only for example, I actually declare the array in a function and not in sub main. Also, I needed the array to be initialized to zeros, so when I googled malloc, I discovered that calloc was perfect for my purposes.

Malloc/calloc also has the advantage over allocating on the stack of allowing me to declare the size using a variable.

Answer 1

Your array is way too big to fit into the stack, consider using the heap:

int *sieve = malloc(2000000 * sizeof(*sieve)); 

If you really want to change the stack size, take a look at this document.

Tip: - Don't forget to free your dynamically allocated memory when it's no-longer needed.

Answer 2

There are 3 ways:

1. Allocate array on heap - use malloc(), as other posters suggested. Do not forget to free() it (although for main() it is not that important - OS will clean up memory for you on program termination).
2. Declare the array on unit level - it will be allocated in data segment and visible for everybody (adding static to declaration will limit the visibility to unit).
3. Declare your array as static - in this case it will be allocated in data segment, but visible only in main().