diff --git a/.idea/vcs.xml b/.idea/vcs.xml
new file mode 100644
index 0000000..35eb1dd
--- /dev/null
+++ b/.idea/vcs.xml
@@ -0,0 +1,6 @@
+
+
+
+
+
+
\ No newline at end of file
diff --git a/src/Main.java b/src/Main.java
index 3e59c38..ad5ee5a 100644
--- a/src/Main.java
+++ b/src/Main.java
@@ -1,5 +1,62 @@
+import edu.greenriver.sdev333.*;
+import java.util.Iterator;
+import java.util.ListIterator;
+
public class Main {
public static void main(String[] args) {
+
System.out.println("Hello world!");
+
+ List friends = new RecursiveLinkedList();
+
+ System.out.println("initial size is " + friends.size());
+
+ friends.add("Jess");
+ friends.add("Tina");
+ friends.add("Josh");
+ friends.add("Susan");
+ friends.add("Tyler");
+ friends.add("Usman");
+ friends.add("Dee");
+ friends.add("Rose");
+ friends.add("Blanche");
+ friends.add("Dorothy");
+ friends.add("Sophia");
+ friends.add(2, "Wednesday");
+ System.out.println("size is now " + friends.size());
+
+ //for (int i = 0; i < friends.size(); i++) {
+ // System.out.println(friends.get(i));
+ //}
+
+ // above: import java.util.Iterator;
+ /*
+ Iterator itr = friends.iterator();
+ while (itr.hasNext()) {
+ String name = itr.next();
+ System.out.println(name);
+ }
+
+
+ for (String name : friends) {
+ System.out.println(name);
+ }
+
+ ListIterator fancyItr = friends.listIterator();
+ while (fancyItr.hasNext()) {
+ String name = fancyItr.next();
+ System.out.println(name);
+ }
+ System.out.println();
+ while (fancyItr.hasPrevious()) {
+ String name = fancyItr.previous();
+ System.out.println(name);
+ }
+
+ */
+
+
+
+
}
}
\ No newline at end of file
diff --git a/src/edu/greenriver/sdev333/ArrayList.java b/src/edu/greenriver/sdev333/ArrayList.java
new file mode 100644
index 0000000..483ec57
--- /dev/null
+++ b/src/edu/greenriver/sdev333/ArrayList.java
@@ -0,0 +1,417 @@
+package edu.greenriver.sdev333;
+
+import java.util.Iterator;
+import java.util.ListIterator;
+
+public class ArrayList implements List {
+
+ // WE NEED FIELDS!!
+
+ // one plain old Java array
+ private ItemType[] data;
+
+ // one int to keep track of size
+ // size is the # of spots that are used in the data array
+ // size is DIFFERENT than length
+ private int size;
+
+
+ public ArrayList() {
+ size = 0;
+ data = (ItemType[]) new Object[10];
+ }
+
+
+ /**
+ * Returns the number of items in this collection.
+ *
+ * @return the number of items in this collection
+ */
+ @Override
+ public int size() {
+ return size;
+ }
+
+ /**
+ * Returns true if this collection contains no items.
+ *
+ * @return true if this collection contains no items
+ */
+ @Override
+ public boolean isEmpty() {
+ if (size == 0) {
+ return true;
+ }
+ return false;
+
+ // alternate way to write it: return size == 0;
+ }
+
+ /**
+ * Returns true if this collection contains the specified item.
+ *
+ * @param item items whose presence in this collection is to be tested
+ * @return true if this collection contains the specified item
+ * @throws NullPointerException if the specified item is null
+ * and this collection does not permit null items
+ */
+ @Override
+ public boolean contains(ItemType item) {
+ int i = indexOf(item);
+ if (i != -1) {
+ return true;
+ }
+
+ return false;
+ }
+
+ /**
+ * Returns an iterator over the elements in this collection.
+ *
+ * @return an Iterator over the elements in this collection
+ */
+ @Override
+ public Iterator iterator() {
+ return new OurCustomIterator();
+ }
+
+ private void checkSize() {
+ if (size == data.length) {
+ // resize up (double up the array size)
+
+ // Step 1 - create a new larger array
+ ItemType[] temp = (ItemType[]) new Object[size * 2];
+
+ // Step 2 - copy items from data to temp
+ for (int i = 0; i < size; i++) {
+ temp[i] = data[i];
+ }
+
+ // Step 3 - repoint/refererence data to point to new array
+ data = temp;
+
+ // Optional:
+ temp = null;
+ } // end of if (need to resize)
+ }
+
+ /**
+ * Adds the specified item to the collection.
+ *
+ * @param item item to be added to the collection
+ * @throws NullPointerException if the specified item is null
+ * and this collection does not permit null items
+ */
+ @Override
+ public void add(ItemType item) {
+
+ checkSize();
+
+ data[size] = item;
+ size++;
+ } // end of method
+
+ /**
+ * Removes a single instance of the specified item from this collection,
+ * if it is present.
+ *
+ * @param item item to be removed from this collection, if present
+ * @throws NullPointerException if the specified item is null
+ * and this collection does not permit null items
+ */
+ @Override
+ public void remove(ItemType item) {
+ int i = indexOf(item);
+ if (i != -1) {
+ // if it's found, use the other remove method to do the work
+ remove(i);
+ }
+
+
+ }
+
+ /**
+ * Removes all items from this collection.
+ * The collection will be empty after this method returns.
+ */
+ @Override
+ public void clear() {
+ // lazy deletion
+ size = 0;
+ }
+
+ /**
+ * Returns true if this collection contains all the items
+ * in the specified other collection.
+ *
+ * @param otherCollection collection to be checked for containment in this collection
+ * @return true if this collection contains all the items
+ * in the specified other collection
+ */
+ @Override
+ public boolean containsAll(Collection otherCollection) {
+
+ Iterator itr = (Iterator)otherCollection.iterator();
+ while (itr.hasNext()) {
+ ItemType itemToCheck = itr.next();
+ if (!contains(itemToCheck)) {
+ return false;
+ }
+ }
+
+ return true;
+
+
+ //for (ItemType itemToCheck : otherCollection) {
+ // if (!contains(itemToCheck)) {
+ // return false;
+ // }
+ //}
+
+ //return true;
+
+ }
+
+ /**
+ * Adds all the items in this specified other collection to this collection.
+ *
+ * @param otherCollection collection containing items to be added to this collection
+ */
+ @Override
+ public void addAll(Collection otherCollection) {
+ throw new UnsupportedOperationException("Not gonna do it!");
+ }
+
+ /**
+ * Removes all of this collection's items that are also contained in the
+ * specified other collection. After this call returns, this collection will
+ * contain no elements in common with the specified other collection.
+ *
+ * @param otherCollection collection containing elements to be removed
+ * from this collection
+ */
+ @Override
+ public void removeAll(Collection otherCollection) {
+
+ }
+
+ /**
+ * Retains only the items in this collection that are contained in the
+ * specified other collection. In other words, removes from this collection
+ * all of its items that are not contained in the specified other collection
+ *
+ * @param otherCollection collection containing elements to be retained in
+ * this collection
+ */
+ @Override
+ public void retainAll(Collection otherCollection) {
+
+ }
+
+ /**
+ * Returns the item at the specified position in this list
+ *
+ * @param index index of the item to return
+ * @return the item at the specified position in this list
+ * @throws IndexOutOfBoundsException if this index is out of range
+ * (index < 0 || index >= size())
+ */
+ @Override
+ public ItemType get(int index) {
+ if (index >= size) {
+ throw new IndexOutOfBoundsException("index is beyond size");
+ }
+
+ return data[index];
+ }
+
+ /**
+ * Replaces the item at the specified position in this list
+ * with the specified item
+ *
+ * @param index index of the item to replace
+ * @param item item to be stored at the specified position
+ * @throws NullPointerException if the specified item is null
+ * and this list does not permit null elements
+ * @throws IndexOutOfBoundsException if the index is out of range
+ * (index < 0 || index >= size())
+ */
+ @Override
+ public void set(int index, ItemType item) {
+ if (index >= size) {
+ throw new IndexOutOfBoundsException("index is beyond size");
+ }
+
+ data[index] = item;
+ }
+
+ /**
+ * Inserts the specified item at the specified position in this list.
+ * Shifts the item currently at that position (if any) and any subsequent
+ * items to the right.
+ *
+ * @param index index at which the specified item is to be inserted
+ * @param item item to be inserted
+ * @throws NullPointerException if the specified item is null
+ * and this list does not permit null elements
+ * @throws IndexOutOfBoundsException if the index is out of range
+ * (index < 0 || index >= size())
+ */
+ @Override
+ public void add(int index, ItemType item) {
+ checkSize();
+
+ for (int i = size; i >= index + 1; i--) {
+ data[i] = data[i - 1];
+ }
+
+ data[index] = item;
+ size++;
+ }
+
+ /**
+ * Removes the element at the specified position in this list.
+ * Shifts any subsequent items to the left.
+ *
+ * @param index the index of the item to be removed
+ * @throws IndexOutOfBoundsException if the index is out of range
+ * (index < 0 || index >= size())
+ */
+ @Override
+ public void remove(int index) {
+ // shift values left to overwrite the item at index
+ for (int i = index; i < size - 1; i++) {
+ data[i] = data[i + 1];
+ }
+ size--;
+ }
+
+ /**
+ * Returns the index of the first occurrence of the specified item
+ * in this list, or -1 if this list does not contain the item.
+ *
+ * @param item the item to search for
+ * @return the index of the first occurrence of the specified item
+ * in this list, or -1 if this list does not contain the item
+ * @throws NullPointerException if the specified item is null and this
+ * list does not permit null items
+ */
+ @Override
+ public int indexOf(ItemType item) {
+
+ for (int i = 0; i < size; i++) {
+ if (item.equals(data[i])) {
+ return i;
+ }
+ }
+
+ // if we got here, it wasn't in the array
+ return -1;
+ }
+
+ /**
+ * Returns the index of the last occurrence of the specified item
+ * in this list, or -1 if this list does not contain the item.
+ *
+ * @param item the item to search for
+ * @return the index of the first occurrence of the specified item
+ * in this list, or -1 if this list does not contain the item
+ * @throws NullPointerException if the specified item is null and this
+ * list does not permit null items
+ */
+ @Override
+ public int lastIndexOf(ItemType item) {
+ return 0;
+ }
+
+ /**
+ * Returns a list iterator over the elements in this list
+ * (in proper sequence).
+ *
+ * @return a list iterator over the elements in this list
+ * (in proper sequence)
+ */
+ @Override
+ public ListIterator listIterator() {
+ return null;
+ }
+
+
+ private class OurCustomIterator implements Iterator {
+ private int currentPosition;
+
+ public OurCustomIterator() {
+ currentPosition = 0;
+ }
+
+ @Override
+ public boolean hasNext() {
+ return currentPosition < size();
+ }
+
+ @Override
+ public ItemType next() {
+ ItemType result = get(currentPosition);
+ currentPosition++;
+ return result;
+ }
+ }
+
+
+ private class SecondCustomIterator implements ListIterator {
+ // fancier Iterator - lets us go forwards and backwards
+ private int currentPosition;
+
+ public SecondCustomIterator() {
+ currentPosition = 0;
+ }
+
+ @Override
+ public boolean hasNext() {
+ return false;
+ }
+
+ @Override
+ public ItemType next() {
+ return null;
+ }
+
+ @Override
+ public boolean hasPrevious() {
+ // hasNext checked currentPosition with size
+ // hasPrevious check currentPosition against 0
+ return false;
+ }
+
+ @Override
+ public ItemType previous() {
+ return null;
+ }
+
+ @Override
+ public int nextIndex() {
+ return 0;
+ }
+
+ @Override
+ public int previousIndex() {
+ return 0;
+ }
+
+ @Override
+ public void remove() {
+
+ }
+
+ @Override
+ public void set(ItemType itemType) {
+
+ }
+
+ @Override
+ public void add(ItemType itemType) {
+
+ }
+ }
+
+} // end of class ArrayList
diff --git a/src/edu/greenriver/sdev333/RecursiveLinkedList.java b/src/edu/greenriver/sdev333/RecursiveLinkedList.java
new file mode 100644
index 0000000..a02a516
--- /dev/null
+++ b/src/edu/greenriver/sdev333/RecursiveLinkedList.java
@@ -0,0 +1,160 @@
+package edu.greenriver.sdev333;
+
+import java.util.Iterator;
+import java.util.ListIterator;
+
+public class RecursiveLinkedList implements List {
+ // private helper class
+ private class Node {
+ ItemType data;
+ Node next;
+ }
+
+ // fields
+ private Node head;
+
+ public RecursiveLinkedList() {
+ head = null;
+ }
+
+ @Override
+ public int size() {
+ return helpSize(head);
+ }
+
+ // private helper method that does the actual recursive work
+ private int helpSize(Node theHead){
+ if (theHead == null) {
+ // base case (the bottom / the end)
+ return 0;
+ }
+ else {
+ // VV "the rest"
+ return helpSize(theHead.next) + 1;
+ }
+ }
+
+ @Override
+ public boolean isEmpty() {
+ return false;
+ }
+
+ @Override
+ public boolean contains(ItemType item) {
+ return false;
+ }
+
+ @Override
+ public Iterator iterator() {
+ return null;
+ }
+
+ @Override
+ public void add(ItemType item) {
+ // adds an item to back
+ // loopy way:
+ // - created a current variable, set it to be same value as head
+ // - wrote a loop while (current.next != null) { current = current.next; }
+ // - once we are at the last node, create new node and attach it
+ head = helpAdd(head, item);
+ }
+
+ private Node helpAdd(Node theHead, ItemType item) {
+ if (theHead == null) {
+ // hit bottom (at the end)
+ Node theNewNode = new Node();
+ theNewNode.data = item;
+ theNewNode.next = null;
+ return theNewNode;
+ }
+ else {
+ // not at end/bottom
+ theHead.next = helpAdd(theHead.next, item);
+ return theHead;
+ }
+ }
+
+ @Override
+ public void remove(ItemType item) {
+
+ }
+
+ @Override
+ public void clear() {
+
+ }
+
+ @Override
+ public boolean containsAll(Collection otherCollection) {
+ return false;
+ }
+
+ @Override
+ public void addAll(Collection otherCollection) {
+
+ }
+
+ @Override
+ public void removeAll(Collection otherCollection) {
+
+ }
+
+ @Override
+ public void retainAll(Collection otherCollection) {
+
+ }
+
+ @Override
+ public ItemType get(int index) {
+ return null;
+ }
+
+ @Override
+ public void set(int index, ItemType item) {
+
+ }
+
+ @Override
+ public void add(int index, ItemType item) {
+ // add(0, item)
+ if (index == 0) {
+ // add to the front - list may or may not be empty
+ Node theNewOne = new Node();
+ theNewOne.data = item;
+ theNewOne.next = head;
+ head = theNewOne;
+ }
+ else {
+ // anywhere else other than 0 (front)
+ Node current = head;
+ for (int i = 0; i < index - 1; i++) {
+ current = current.next;
+ }
+
+ Node theNewOne = new Node();
+ theNewOne.data = item;
+ theNewOne.next = current.next;
+ current.next = theNewOne;
+ }
+ }
+
+ @Override
+ public void remove(int index) {
+
+ }
+
+ @Override
+ public int indexOf(ItemType item) {
+ return 0;
+ }
+
+ @Override
+ public int lastIndexOf(ItemType item) {
+ return 0;
+ }
+
+ @Override
+ public ListIterator listIterator() {
+ return null;
+ }
+}
diff --git a/src/edu/greenriver/sdev333/SinglyLinkedList.java b/src/edu/greenriver/sdev333/SinglyLinkedList.java
new file mode 100644
index 0000000..4ae2b20
--- /dev/null
+++ b/src/edu/greenriver/sdev333/SinglyLinkedList.java
@@ -0,0 +1,487 @@
+package edu.greenriver.sdev333;
+
+import javax.naming.OperationNotSupportedException;
+import java.util.Iterator;
+import java.util.ListIterator;
+
+public class SinglyLinkedList implements List {
+
+ // FIELDS - what does a linked list actually have in it??
+ private Node head;
+ private int size;
+
+ // helper/inner classes
+ private class Node {
+ ItemType data;
+ Node next;
+ }
+
+ /**
+ * Constructor
+ */
+ public SinglyLinkedList() {
+ // an empty list has no nodes,
+ // which means it has no head, so set head to null
+ head = null;
+ size = 0;
+ }
+
+ /**
+ * Returns the number of items in this collection.
+ *
+ * @return the number of items in this collection
+ */
+ @Override
+ public int size() {
+ return size;
+ }
+
+ /**
+ * Returns true if this collection contains no items.
+ *
+ * @return true if this collection contains no items
+ */
+ @Override
+ public boolean isEmpty() {
+ return size == 0;
+ }
+
+ /**
+ * Returns true if this collection contains the specified item.
+ *
+ * @param item items whose presence in this collection is to be tested
+ * @return true if this collection contains the specified item
+ * @throws NullPointerException if the specified item is null
+ * and this collection does not permit null items
+ */
+ @Override
+ public boolean contains(ItemType item) {
+ // assume indexOf is working...
+ int position = indexOf(item);
+ if (position == -1) {
+ return false;
+ }
+ return true;
+ }
+
+ /**
+ * Returns an iterator over the elements in this collection.
+ *
+ * @return an Iterator over the elements in this collection
+ */
+ @Override
+ public Iterator iterator() {
+ return new OurCustomIterator();
+ }
+
+ /**
+ * Adds the specified item to the collection.
+ *
+ * @param item item to be added to the collection
+ * @throws NullPointerException if the specified item is null
+ * and this collection does not permit null items
+ */
+ @Override
+ public void add(ItemType item) {
+ if (item == null) {
+ throw new NullPointerException();
+ }
+ // the index at the end of the list is size - 1
+ // example: if list is size 5, last index is 4
+ // so we can just insert at the last index
+ add(size() - 1, item);
+ }
+
+ /**
+ * Removes a single instance of the specified item from this collection,
+ * if it is present.
+ *
+ * @param item item to be removed from this collection, if present
+ * @throws NullPointerException if the specified item is null
+ * and this collection does not permit null items
+ */
+ @Override
+ public void remove(ItemType item) {
+ if (item == null) {
+ throw new NullPointerException();
+ }
+
+ // alternative - easier to write, but less efficient
+ /*
+ int position = indexOf(item);
+ if (position != -1) {
+ remove(position);
+ }
+ */
+
+ if (head.data == item) {
+ head = head.next;
+ size--;
+ }
+ else {
+ Node current = head;
+ Node previous;
+ while (current.next != null) {
+ previous = current;
+ current = current.next;
+
+ if (current.data.equals(item)) {
+ previous.next = current.next;
+ size--;
+ }
+ }
+ }
+
+ }
+
+ /**
+ * Removes all items from this collection.
+ * The collection will be empty after this method returns.
+ */
+ @Override
+ public void clear() {
+ head = null;
+ size = 0;
+ }
+
+ /**
+ * Returns true if this collection contains all the items
+ * in the specified other collection.
+ *
+ * @param otherCollection collection to be checked for containment in this collection
+ * @return true if this collection contains all the items
+ * in the specified other collection
+ */
+ @Override
+ public boolean containsAll(Collection otherCollection) {
+ for (ItemType item : otherCollection) {
+ if (!this.contains(item)) {
+ return false;
+ }
+ }
+ return true;
+
+ /*
+ Iterator itr = (Iterator)otherCollection.iterator();
+ while (itr.hasNext()) {
+ ItemType item = itr.next();
+ if (!contains(item)) {
+ return false;
+ }
+ }
+
+ return true;
+ */
+
+ }
+
+ /**
+ * Adds all the items in this specified other collection to this collection.
+ *
+ * @param otherCollection collection containing items to be added to this collection
+ */
+ @Override
+ public void addAll(Collection otherCollection) {
+ // walk through the other collection
+ // for-each loop
+ // or use Iterator
+
+ Iterator itr = (Iterator)otherCollection.iterator();
+ while (itr.hasNext()) {
+ ItemType currentItem = itr.next();
+ add(currentItem);
+ }
+
+ /*
+ // alternative implementation using a for-each loop
+ for (ItemType currentItem : otherCollection) {
+ add(currentItem);
+ }
+ */
+ }
+
+ /**
+ * Removes all of this collection's items that are also contained in the
+ * specified other collection. After this call returns, this collection will
+ * contain no elements in common with the specified other collection.
+ *
+ * @param otherCollection collection containing elements to be removed
+ * from this collection
+ */
+ @Override
+ public void removeAll(Collection otherCollection) {
+
+ }
+
+ /**
+ * Retains only the items in this collection that are contained in the
+ * specified other collection. In other words, removes from this collection
+ * all of its items that are not contained in the specified other collection
+ *
+ * @param otherCollection collection containing elements to be retained in
+ * this collection
+ */
+ @Override
+ public void retainAll(Collection otherCollection) {
+
+ }
+
+ /**
+ * Returns the item at the specified position in this list
+ *
+ * @param index index of the item to return
+ * @return the item at the specified position in this list
+ * @throws IndexOutOfBoundsException if this index is out of range
+ * (index < 0 || index >= size())
+ */
+ @Override
+ public ItemType get(int index) {
+ if (index < 0 || index >= size) {
+ throw new IndexOutOfBoundsException();
+ }
+
+ Node current = head;
+ int counter = 0;
+ while (counter != index) {
+ current = current.next;
+ counter++;
+ }
+ return current.data;
+
+ /*for (int i = 0; i < index; i++) {
+ current = current.next;
+ }*/
+ }
+
+ /**
+ * Replaces the item at the specified position in this list
+ * with the specified item
+ *
+ * @param index index of the item to replace
+ * @param item item to be stored at the specified position
+ * @throws NullPointerException if the specified item is null
+ * and this list does not permit null elements
+ * @throws IndexOutOfBoundsException if the index is out of range
+ * (index < 0 || index >= size())
+ */
+ @Override
+ public void set(int index, ItemType item) {
+
+ }
+
+ /**
+ * Inserts the specified item at the specified position in this list.
+ * Shifts the item currently at that position (if any) and any subsequent
+ * items to the right.
+ *
+ * @param index index at which the specified item is to be inserted
+ * @param item item to be inserted
+ * @throws NullPointerException if the specified item is null
+ * and this list does not permit null elements
+ * @throws IndexOutOfBoundsException if the index is out of range
+ * (index < 0 || index >= size())
+ */
+ @Override
+ public void add(int index, ItemType item) {
+ checkIndex(index);
+
+ if (index == 0) {
+ // if someone wants to add at the beginning, I need to change the head
+ Node theNewOne = new Node();
+ theNewOne.data = item;
+ theNewOne.next = head;
+ head = theNewOne;
+ }
+ else {
+ Node current = head;
+
+ // stop one before the position I want to insert at
+ for (int i = 0; i < index - 1; i++) {
+ current = current.next;
+ }
+
+ // when I get here, current is pointing the node *BEFORE* the node at the index
+ Node theNewOne = new Node();
+ theNewOne.data = item;
+ theNewOne.next = current.next;
+
+ current.next = theNewOne;
+ }
+
+ size++;
+ }
+
+ private void checkIndex(int index) {
+ if (index < 0 || index >= size) {
+ throw new IndexOutOfBoundsException();
+ }
+ }
+
+ /**
+ * Removes the element at the specified position in this list.
+ * Shifts any subsequent items to the left.
+ *
+ * @param index the index of the item to be removed
+ * @throws IndexOutOfBoundsException if the index is out of range
+ * (index < 0 || index >= size())
+ */
+ @Override
+ public void remove(int index) {
+ checkIndex(index);
+
+ if (index == 0) {
+ head = head.next;
+ }
+ else {
+ Node current = head;
+ for (int i = 0; i < index - 1; i++) {
+ current = current.next;
+ }
+ // when I get here - current is pointing to the node BEFORE the one at index
+
+ current.next = current.next.next;
+ }
+
+ size--;
+
+ }
+
+ /**
+ * Returns the index of the first occurrence of the specified item
+ * in this list, or -1 if this list does not contain the item.
+ *
+ * @param item the item to search for
+ * @return the index of the first occurrence of the specified item
+ * in this list, or -1 if this list does not contain the item
+ * @throws NullPointerException if the specified item is null and this
+ * list does not permit null items
+ */
+ @Override
+ public int indexOf(ItemType item) {
+ int counter = 0;
+ Node current = head;
+ while (current != null) {
+ if (current.data.equals(item)) {
+ return counter;
+ }
+ counter++;
+ current = current.next;
+ }
+
+ // if we get here, it's not found
+ return -1;
+ }
+
+ /**
+ * Returns the index of the last occurrence of the specified item
+ * in this list, or -1 if this list does not contain the item.
+ *
+ * @param item the item to search for
+ * @return the index of the first occurrence of the specified item
+ * in this list, or -1 if this list does not contain the item
+ * @throws NullPointerException if the specified item is null and this
+ * list does not permit null items
+ */
+ @Override
+ public int lastIndexOf(ItemType item) {
+ return 0;
+ }
+
+ /**
+ * Returns a list iterator over the elements in this list
+ * (in proper sequence).
+ *
+ * @return a list iterator over the elements in this list
+ * (in proper sequence)
+ */
+ @Override
+ public ListIterator listIterator() {
+ return new OurEnhancedIterator();
+ }
+
+ private class OurCustomIterator implements Iterator {
+
+ // field
+ private Node currentPosition;
+
+ public OurCustomIterator() {
+ currentPosition = head;
+ }
+
+ @Override
+ public boolean hasNext() {
+ // see if I'm on the last node: if (current.next == null)
+ // see if I made it past the last node: if (current == null)
+ if (currentPosition != null) {
+ return true;
+ }
+ return false;
+ }
+
+ @Override
+ public ItemType next() {
+ ItemType result = currentPosition.data;
+ currentPosition = currentPosition.next;
+ return result;
+ }
+ }
+
+ private class OurEnhancedIterator implements ListIterator {
+
+ private Node currentPosition;
+ private int currentIndex;
+
+ public OurEnhancedIterator() {
+ currentPosition = head;
+ currentIndex = 0;
+ }
+
+ @Override
+ public boolean hasNext() {
+ return currentPosition != null;
+ }
+
+ @Override
+ public ItemType next() {
+ ItemType result = currentPosition.data;
+ currentPosition = currentPosition.next;
+ return result;
+ }
+
+ @Override
+ public boolean hasPrevious() {
+ return false;
+ }
+
+ @Override
+ public ItemType previous() {
+ return null;
+ }
+
+ @Override
+ public int nextIndex() {
+ return 0;
+ }
+
+ @Override
+ public int previousIndex() {
+ return 0;
+ }
+
+ @Override
+ public void remove() {
+
+ }
+
+ @Override
+ public void set(ItemType itemType) {
+
+ }
+
+ @Override
+ public void add(ItemType itemType) {
+
+ }
+ }
+
+}