List::List(const List &other):
first(nullptr), last(nullptr), currentSize(0), def(0)
{
for (ListItem *item = other.first; item != nullptr; item = item->getNext()) {
appendElement(item->getContent());
}
}
List::List(const List& other):
first(nullptr), last(nullptr), currentSize(0)
{
// Copy list item-wise to avoid having two lists pointing at the same list items
for (ListItem *item = other.first; item != nullptr; item = item->getNext()) {
appendElement(item->getContent());
}
}
int& List::getNthElement(int n) {
int index = n;
ListItem* p = first;
// iterate over elements
while (index-- > 0) {
p = p->getNext();
}
return p->getContent();
}
int &List::getNthElement(int n) {
if (currentSize >= n + 1 && n >= 0) {
ListItem* tmp = first;
for (int i = 0; i < n; i++) {
tmp = tmp->getNext();
}
return tmp->getContent();
}
else
throw std::out_of_range("List index out of range");
}
int List::deleteFirst() {
if (currentSize != 0) {
int tmp = first->getContent();
ListItem *del = first;
first = del->getNext();
delete del;
currentSize--;
return tmp;
}
else
return 0;
}
void List::insertElementAt(int i, int pos) {
if (pos <= 0)
prependElement(i);
else if (pos >= getSize())
appendElement(i);
else {
ListItem *tmp = first;
while (pos-- > 0) {
tmp = tmp->getNext();
}
new ListItem(tmp->getPrevious(), tmp, i);
currentSize++;
}
}
int List::deleteAt(int pos) {
if (pos <= 0)
return deleteFirst();
else if (pos >= getSize())
return deleteLast();
else {
ListItem *del = first;
while (pos-- > 0) {
del = del->getNext();
}
int val = del->getContent();
delete del;
currentSize--;
return val;
}
}
void List::insertElementAt(int i, int pos) {
if (pos <= 0) {
prependElement(i);
}
else if (pos >= getSize()) {
appendElement(i);
}
else {
ListItem* p = first;
// iterate over elements
while (pos-- > 0) {
p = p->getNext();
}
new ListItem(p->getPrevious(), p, i);
++currentSize;
}
}
int List::deleteAt(int pos) {
if (pos <= 0) {
return deleteFirst();
}
else if (pos >= currentSize - 1) {
return deleteLast();
}
else {
int index = pos;
ListItem* p = first;
// iterate over elements
while (index-- > 0) {
p = p->getNext();
}
int content = p->getContent();
delete p;
--currentSize;
return content;
}
}
void inheritanceClassDemo()
{
ListItem *item;
/* Lets see how the items are created. Please use step into the
* see how the next instruction creates an element.
*/
IntListItem intItem0(0);
/* Now lets see it create a different type of item. Please use
* step into the see this go to the FloatListItem constructor.
*/
FloatListItem floatItem0(1.0);
/* Now we will start adding items to lists. We will create one
* list that may contain either Integers or Floats.
*/
List linkedList;
/* Let's start adding to the list. Items will be added to the end
* of the list.
*/
linkedList.add(intItem0);
linkedList.add(intItem1);
linkedList.add(intItem2);
linkedList.add(floatItem0);
linkedList.add(floatItem1);
linkedList.add(floatItem2);
/* Display the contents of the linked list. Notice a mixture of integers
* and floating numbers are inserted into the list. The "displayValue"
* function for these items will be resolved at runtime since "item" is a
* pointer to the base class ListItem.
*/
for (item = linkedList.getFirst();
item != 0;
item = item->getNext())
{
item->displayValue();
}
/* Remove the items from the list.
*/
while (linkedList.getFirst() != 0)
{
linkedList.remove(*(linkedList.getFirst()));
}
/* If you stepped into during the adds, you would have seen how
* that the member function "add" for List was called. Now we will
* create another list that is sorted using SortedList which
* derives from List, but changes the add function to sort the
* list.
*
* NOTE: We will be using the overridded member function "compare"
* in the ListItem for each of the derived classes
* "IntListItem" and "FloatListItem". Since these cannot be
* compared between each other we will create two classes;
* one for integers and one for floats.
*/
SortedList intList;
SortedList floatList;
/* Add the first items. Please step into the next instructions to
* see how the "compare" member function get called for
* IntListItem and FloatListItem. Also notice how the "add" member
* function get called in the SortedList Class.
*/
intList.add(intItem1);
floatList.add(floatItem1);
/* Now lets add something to the front of the list.
*/
intList.add(intItem0);
floatList.add(floatItem0);
/* Now to the end of the list.
*/
intList.add(intItem3);
floatList.add(floatItem3);
/* Now in the middle.
*/
intList.add(intItem2);
floatList.add(floatItem2);
/* Display the contents of the sorted integer linked list.
*/
for (item = intList.getFirst();
item != 0;
item = item->getNext())
{
item->displayValue();
}
/* Display the contents of the sorted floating linked list.
*/
for (item = floatList.getFirst();
item != 0;
item = item->getNext())
{
item->displayValue();
}
}