The following code crashes when compiled with MS VC 2013 Express (Windows 7, 64 bit computer):
#define N 1000*1000
for (i = 0; i < N; i++)
x[i] = (float) (rand() + 1) / RAND_MAX;
You're basically trying to allocate an array of 1000000 elements, which is simply too big. It's just too huge for programs stack space.
Result: Stack overflow.
Side effect: Undefined behavior, crash.
Solution: Allocate that array in heap. Take a pointer, allocate memory using memory allocator function and you may be able to get it going.
Though arrays are not pointers but for most of the cases, a replacement like (in
float * x = malloc(N * (sizeof *x)); // for simplicity, omitting obligatory free, // success check, stdlib inclusion etc.
That said, the actual solution would be, re-plan the program design, normally you should not be needing an array that large, try to make the design more modular and process in parts, as and when required.