Java/DataStructures/Lists/CircleLinkedList.java at master · loisoft/Java · GitHub

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package DataStructures.Lists;

public class CircleLinkedList<E> {

private static class Node<E> {

Node<E> next;

E value;

private Node(E value, Node<E> next) {

this.value = value;

this.next = next;

}

// For better O.O design this should be private allows for better black box design

private int size;

// this will point to dummy node;

private Node<E> head = null;

// constructer for class.. here we will make a dummy node for circly linked list implementation

// with reduced error catching as our list will never be empty;

public CircleLinkedList() {

// creation of the dummy node

head = new Node<E>(null, head);

size = 0;

}

// getter for the size... needed because size is private.

public int getSize() {

return size;

}

// for the sake of simplistiy this class will only contain the append function or addLast other

// add functions can be implemented however this is the basses of them all really.

public void append(E value) {

if (value == null) {

// we do not want to add null elements to the list.

throw new NullPointerException("Cannot add null element to the list");

}

// head.next points to the last element;

head.next = new Node<E>(value, head);

size++;

}

public E remove(int pos) {

if (pos > size || pos < 0) {

// catching errors

throw new IndexOutOfBoundsException("position cannot be greater than size or negative");

}

// we need to keep track of the element before the element we want to remove we can see why

// bellow.

Node<E> before = head;

for (int i = 1; i <= pos; i++) {

before = before.next;

}

Node<E> destroy = before.next;

E saved = destroy.value;

// assigning the next reference to the the element following the element we want to remove...

// the last element will be assigned to the head.

before.next = before.next.next;

// scrubbing

destroy = null;

size--;

return saved;

}

Java/DataStructures/Lists/CircleLinkedList.java at master · loisoft/Java · GitHub

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