Thread: Trying to Understand Structure

I'm still pretty new to C and still do not have a good grasp on pointers and structures.

I'm working on a program that globally declares a nested? structure, and globally declares another structure that I believe is related:

Code:

static struct alist {         /*  Nodes of linked list: Paths */
   int *p;                    /*  Array of paths              */
   struct alist *Next;        /*  Next path                   */
};

static struct alist **Saved;        /* Saved paths               */

There is a function named ev_num that does something with these functions:

Code:

Saved =  (struct alist **) malloc(sizeof(struct alist*));   
  *Saved = (struct alist *)NULL;    /* Linked list of saved paths */

 GetPath( m, r );                  /* Get the paths */

Does anyone understand what' going on with the above code? Any help would be appreciated because I'm pretty lost.

Basically, how would I go about getting values out of this structure?

The first thing is to remove all those redundant casts on assigning the result of malloc, and assigning NULL (this is C after all)

Given say
struct alist *foo = *saved;

Then you could do
foo->p[0] = 0;
to access the first element of your array

and
foo = foo->Next;
to advance to the next node.

This is typical for traversing linked lists

Code:

while ( foo != NULL ) {
  // do stuff
  foo = foo->Next;
}

This kind of learning is a bad practice. Try learning by a good book or tutorial step by step.