A segmentation fault error with 2D array

Question

There is a weird segmentation fault error. The following code runs fine

#include  
#include 
main()
    {
    int matrixSize = 100         


        

Answer 1

As tpg2114 says allocating as large matrices is not a good idea. Easiest is to allocate it like that

double (*a)[matrixSize] = malloc(sizeof(double[matrixSize][matrixSize]));
.
free(a);

Then you can continue to use your nested for loops for initialization without problems as before.

NB:

• since you use a variable for the dimensions your matrix is technically a variable length array, that is only available with C99
• your definition for main is not conforming to the standard. In your case you should use int main(void) { ... }. since a conforming compiler should capture this, it looks that you don't use the correct options for your compiler or that you ignore warnings that he gives you.
• since they are representing sizes, your variables matrixSize, i and j should be of type size_t and not int.