如何使用指针和数组访问嵌套结构？

Question

typedef struct
{
    unsigned int a;
    unsigned char b[10];
    unsigned char c;
}acc1;

typedef struct
{
    unsigned char z[10];
    acc1 *x,y[10];
}acc2;

extern acc2 p[2];

I want to access struct acc1 variables from acc2 array p[2] .

I'm getting segmenatation faults when I do it. Please guide on how to do this

Answer 1

To access y 's elements do:

char c = p[some index between 0 and 1].y[some index between 0 and 9].c

To access elements referred to by x do:

size_t i = some index between 0 and 1;
p[i].x = malloc(somenumber_of_elements * sizeof *p[i].x);
if (NULL == p[i].x)
{
  abort(); /* Failure to allocate memory. */
}
char c = p[i].x[some index less then somenumber_of_elements].c;

---

Referring kabhis comment

p[0].x->c is it not correct ?

Assuming the allocation above with somenumber_of_elements greater 0 , then:

char c = p[i].x[0].c;

is equivalent to

char c = p[i].x->c;

and for somenumber_of_elements greater 1

char c = p[i].x[1].c;

is equivalent to

char c = (p[i].x + 1)->c;

and so on ...