#include <stdlib.h>
#include "stack.h"

//TODO: grundlegende Stackfunktionen implementieren:
/*  * `push`: legt ein Element oben auf den Stack,
    * `pop`: entfernt das oberste Element,
    * `top`: liefert das oberste Element zurück,
    * `clearStack`: gibt den gesamten Speicher frei. */

// Pushes data as pointer onto the stack.
StackNode *push(StackNode *stack, void *data)
{

}

// Deletes the top element of the stack (latest added element) and releases its memory. (Pointer to data has to be
// freed by caller.)
StackNode *pop(StackNode *stack)
{

}

// Returns the data of the top element.
void *top(StackNode *stack)
{
    if (stack == NULL)
    {
        return;
    }
    else
    {
        return stack->data;
    }
}

// Clears stack and releases all memory.
void clearStack(StackNode *stack)
{
    StackNode *head = stack;
    StackNode *current = head;
    while(current)
    {
        free(current->data);
		StackNode *nextNode = current->next;
        free(current);
        current = nextNode;
    }
    head = NULL;
}