C Programming Structs / Dynamic Mem

Question

typedef struct {
  char * fname; 
  char * lname;
} single_entry;

I'm going through an exercise where we can't use:

single_entry * next; 

To create a linked list.

How can I accomplish the same thing without using a linked list? I'm thinking making another struct like this?

typedef struct {
  single_entry * next;
} myEntry;

How would I use this though? I'm so familiar with everything just in one struct.

Answer 1

typedef struct 
{
    char *fname; 
    char *lname;
} single_entry;

typedef struct
{
    single_entry *array;
    unsigned size, capacity;
} se_array;

void initialise(se_array *sarray)
{
    sarray->size = 0;
    sarray->capacity = 0;
}

void add_to_array(se_array *sarray, single_entry entry)
{
    if(sarray->capacity == 0)
    {
        sarray->array = malloc(sizeof(single_entry) * (sarray->capacity = 3));
        sarray->array[sarray->size++] = entry;
    }
    else if(sarray->capacity == sarray->size)
    {
    sarray->array = realloc(sarray->array, sizeof(single_entry) * (sarray->capacity *= 1.5));
    sarray->array[sarray->size++] = entry;
    }
    else
    {
    sarray->array[sarray->size++] = entry;
    }
}

int main(void)
{
    se_array my_array;
    initialise(&my_array);
    single_entry my_entry;
    strcpy(my_entry.fname, "first");
    strcpy(my_entry.lname, "last");
    add_to_array(&my_array, my_entry);
    my_array.array[0].fname; // element 0 fname
}