int list_get(LinkedList *list, int iPosition)
{
list_alloc_test(list);
Element *elementCurrent;
// Check if position asked is present in the list.
if (iPosition > list->size - 1)
{
printf("ERROR. The list only contains %d elements.\n", list->size);
return -1;
}
else
{
// We need to go through the list to acced to the iPosition element.
int i;
elementCurrent = list->first;
for (i = 0; i < iPosition; i++)
{
elementCurrent = elementCurrent->next;
}
// Now we reached the iPosition element of the list.
return elementCurrent->value;
}
}
void list_destroy(LinkedList *list)
{
list_alloc_test(list);
Element *element = list->first;
while (element) {
Element *next = element->next;
free(element);
element = next;
}
free(list);
}
void list_destroy(LinkedList *list)
{
list_alloc_test(list);
Element *elementCurrent, *elementNext;
elementCurrent = list->first;
while (elementCurrent != NULL)
{
elementNext = elementCurrent->next;
free(elementCurrent);
elementCurrent = elementNext;
}
free(elementCurrent);
free(elementNext);
free(list);
}
void list_add(LinkedList *list, int iValueToAdd)
{
list_alloc_test(list);
// We allocate memory for the new element that will be added.
Element *element = malloc(sizeof(*element));
if (element == NULL)
{
exit(EXIT_FAILURE);
}
// We initialize the element.
element->value = iValueToAdd;
// the next element is null because we add at the end of the list.
element->next = NULL;
// If the list was empty
if (list->size == 0)
{
// Be careful we need to free the first element because it was
// initiated.
free(list->first);
element->previous = NULL;
list->first = element;
}
// If the list already contains at least one other element.
else
{
element->previous = list->last;
list->last->next = element;
}
list->last = element;
list->size += 1;
}
void list_print(LinkedList *list)
{
// We will go through the list and print each of the element.s
list_alloc_test(list);
Element *elementCurrent;
printf("{");
if (list->size > 0)
{
elementCurrent = list->first;
while (elementCurrent != NULL)
{
printf("%d", elementCurrent->value);
elementCurrent = elementCurrent->next;
if (elementCurrent != NULL)
{
printf(", ");
}
}
}
printf("}\n");
}
void list_del(LinkedList *list, int iValueToDel)
{
list_alloc_test(list);
Element *elementCurrent, *elementPrevious;
// List empty
if (list->size == 0)
{
printf("ERROR. List is empty, nothing to delete\n");
}
// List contains only one element
else if (list->size == 1)
{
elementCurrent = list->first;
if (elementCurrent->value == iValueToDel)
{
free(elementCurrent);
list->first = NULL;
list->last = NULL;
list->size = 0;
}
else
{
printf("ERROR. Element not in list, nothing to delete\n");
}
}
// List has at least two elements
else
{
elementPrevious = list->first;
elementCurrent = elementPrevious->next;
// Element to delete is the first one
if (elementPrevious->value == iValueToDel)
{
list->first = elementCurrent;
elementCurrent->previous = NULL;
list->size -= 1;
free(elementPrevious);
}
// Element to delete is not the first
else
{
// Loop to check if any of the value of the elements is iValueToDel
int iKeepGoing = 1;
while (elementCurrent != NULL && iKeepGoing == 1)
{
if (elementCurrent->value == iValueToDel)
{
iKeepGoing = 0;
elementPrevious->next = elementCurrent->next;
list->size -= 1;
// if we are deleting the last element
if (elementCurrent->next == NULL)
{
list->last = elementPrevious;
}
else
{
elementCurrent->next->previous = elementPrevious;
}
free(elementCurrent);
}
else
{
elementPrevious = elementCurrent;
elementCurrent = elementCurrent->next;
}
}
// Feedback if element was not found
if (iKeepGoing == 1)
{
printf("ERROR. Element not found.\n");
}
}
}
}
