i don't know what I hate segfaults

custom_c_arrays.c

typedef struct {
  int size;
  short *digits;
} IntArray;

typedef struct {
  int size;
  IntArray **arrays;
} IntArrayOfArray;

/* pretend an IntArray of size:5 digits[1,2,3,4,5], piecePer:3 */
IntArrayOfArray * functionminified (IntArray *input, int piecePer) {
  IntArrayOfArray *rtv = (IntArrayOfArray *) malloc(sizeof(IntArrayOfArray));
  rtv->size = floor(input->size / piecePer);
  rtv->arrays = (IntArray *) malloc(rtv->size * sizeof(IntArray));
  rtv->arrays[0]->size = 0; // segfaults
  // ..
  // ..
  return rtv;
}