Thread: Been looking at this linked list i made but can't see where it goes wrong

I wanted to create some sort of linked list pointing to the array position rather than using pointers, since i was going for only allocating memory statically.

Code:

int object_index()
{
    int index;


    // Gets a unique index number


    // First it looks for a recycled number
    if (obj_recycle_size > 0) {
        obj_recycle_size--;
        index = obj_recycled[obj_recycle_size];
    }
    // Otherwise it generates a new one
    else {
        index = objIndex_size++;
    }


    // Links the new index into the chain


    // Add first
    if (objHead == UNDEFINED) {
        objHead = index;
        objHead = index;
        printf("has no head!\n");
        if (objTail == UNDEFINED) {
            printf("has no tail!\n");
            objTail = index;
        }
        object[index].prev = UNDEFINED;    // define previous node
    }
    // Add after
    else {
        object[objTail].next = index;
        object[index].prev = objTail;    // define previous node
        objTail = index;
    }
    object[index].next = UNDEFINED;        // define next node


    int i = objHead;

    // Debug -iterates through the current list after each added object
    while (i != UNDEFINED) {
        int prev = object[i].prev;
        int next = object[i].next;
        printf("%d->%d->%d || %d %d\n", prev, i, next, objHead, objTail);
        i = object[i].next;
        if (i == UNDEFINED)
            printf("-----\n");
    }


    return index;
}

However if i create 3 objects the output is the following:

as no head!
has no tail!
9999->0->9999 || 0 0 ----------- so far so good.
9999->0->1 || 0 1
0->1->9999 || 0 1 ----------- this looks proper too
9999->0->1 || 0 2
9999->1->2 || 0 2 ----------- I can't understand why it would lose it's previous value here......
1->2->9999 || 0 2

The "add first" part could just be

Code:

    if (objHead == UNDEFINED) {
        objHead = objTail = index;
        object[index].prev = UNDEFINED;
    }

But it basically looks okay. You'd have to show some complete, runnable code for any more help.