[Solved] CS113-Homework 3 Double Linked List Implementation

Provide your implementation for a `DoubleLinkedList<E>`**. Apart from a default constructor and `toString()` method, make sure to implement the methods from the `List` interface and create an inner class implementing `ListIterator` interface (in addition to the necessary static inner class `Node<E>`). **You will be graded on having all the methods below implemented and passing all JUnit tests for the `List` interface in addition to the JUnit tests for its `ListIterator`.** Feel free to use code from the book (`KWLinkedList`) or slides.

`ListIterator` interface [methods](https://docs.oracle.com/javase/7/docs/api/java/util/ListIterator.html) to implement:

| return type | method + description ||||| `void` | `add(E e)` || | Inserts the specified element into the list (optional operation). || `boolean` | `hasNext()` || | Returns true if this list iterator has more elements when traversing the list in the forward direction. || `boolean` | `hasPrevious()` || | Returns true if this list iterator has more elements when traversing the list in the reverse direction. || `E` | `next()` || | Returns the next element in the list and advances the cursor position. || `int` | `nextIndex()` || | Returns the index of the element that would be returned by a subsequent call to next(). || `E` | `previous()` || | Returns the previous element in the list and moves the cursor position backwards. || `int` | `previousIndex()` || | Returns the index of the element that would be returned by a subsequent call to previous(). || `void` | `remove()` || | Removes from the list the last element that was returned by next() or previous() (optional operation). || `void` | `set(E e)` || | Replaces the last element returned by next() or previous() with the specified element (optional operation). |

`List` Interface [methods](https://docs.oracle.com/javase/7/docs/api/java/util/List.html) to implement:

| return type | method + description ||||| `Iterator<E>` | `iterator()` || | Returns an iterator over the elements in this list in proper sequence. || `ListIterator<E>` | `listIterator()` || | Returns a list iterator over the elements in this list (in proper sequence). || `ListIterator<E>` | `listIterator(int index)` || | Returns a list iterator over the elements in this list (in proper sequence), starting at the specified position in the list. || `boolean` | `add(E e)` || | Appends the specified element to the end of this list (optional operation). || `void` | `add(int index, E element)` || | Inserts the specified element at the specified position in this list (optional operation). || `void` | `clear()` || | Removes all of the elements from this list (optional operation). || `boolean` | `equals(Object o)` || | Compares the specified object with this list for equality. || `boolean` | `contains(Object o)` || | Returns true if this list contains the specified element. || `E` | `get(int index)` || | Returns the element at the specified position in this list. || `int` | `indexOf(Object o)` || | Returns the index of the first occurrence of the specified element in this list, or -1 if this list does not contain the element. || `int` | `lastIndexOf(Object o)` || | Returns the index of the last occurrence of the specified element in this list, or -1 if this list does not contain the element. || `boolean` | `isEmpty()` || | Returns true if this list contains no elements. || `E` | `remove(int index)` || | Removes the element at the specified position in this list (optional operation). || `boolean` | `remove(Object o)` || | Removes the first occurrence of the specified element from this list, if it is present (optional operation). || `E` | `set(int index, E element)` || | Replaces the element at the specified position in this list with the specified element (optional operation). || `int` | `size()` || | Returns the number of elements in this list. |

These are the rest of the`List` interface methods (**do not build these**, we will implement them later):

| return type | method + description ||||| `List<E>` | `subList(int fromIndex, int toIndex)` || | Returns a view of the portion of this list between the specified fromIndex, inclusive, and toIndex, exclusive. || `Object[]` | `toArray()` || | Returns an array containing all of the elements in this list in proper sequence (from first to last element). || `boolean` | `addAll(Collection<? extends E> c)` || | Appends all of the elements in the specified collection to the end of this list, in the order that they are returned by the specified collections iterator (optional operation). || `boolean` | `addAll(int index, Collection<? extends E> c)` || | Inserts all of the elements in the specified collection into this list at the specified position (optional operation). || `boolean` | `containsAll(Collection<?> c)` || | Returns true if this list contains all of the elements of the specified collection. || `boolean` | `removeAll(Collection<?> c)` || | Removes from this list all of its elements that are contained in the specified collection (optional operation). || `int` | `hashCode()` || | Returns the hash code value for this list. || `default void` | `replaceAll(UnaryOperator<E> operator)` || | Replaces each element of this list with the result of applying the operator to that element. || `boolean` | `retainAll(Collection<?> c)` || | Retains only the elements in this list that are contained in the specified collection (optional operation). || `<T> T[]` | `toArray(T[] a)` || | Returns an array containing all of the elements in this list in proper sequence (from first to last element); the runtime type of the returned array is that of the specified array. || `default void` | `sort(Comparator<? super E> c)` || | Sorts this list according to the order induced by the specified Comparator. || `default Spliterator<E>` | `spliterator()` || | Creates a Spliterator over the elements in this list. |

–

### Make sure to commit + push *before* the deadline to have your code be considered for grading.

>Pro-Tips:>- Build the constructor and `toString` first, then build the `ListIterator` implementation to help you build the `List` interface methods.>- **You dont need to document any methods that are overridden!** By using the `@Override` JavaDoc tag, when you generate the JavaDoc it will automatically connect the inherited documentation! Just dont forget to document constructors, helper methods, etc. ***#thanksJavaDoc***>- Note that out of the ***Do not implement*** `List` interface methods, you have the knowledge to get the first 6 working! Since the parameters are `Collection` types (and every data structure we have built/will build implements `Collection`), you are familiar with most of the [standard methods](https://docs.oracle.com/javase/7/docs/api/java/util/Collection.html) it contains. Try implementing them if you have some spare time!