package linklist;/** * @Title: LinkedListDemo * @ProjectName demo */public class LinkedListDemo
     
       {    private class Node {        private E e;        private Node next;        public Node(E e, Node next) {            this.e = e;            this.next = next;        }        public Node(E e) {            this(e, null);        }        public Node() {            this(null, null);        }        @Override        public String toString() {            return e.toString();        }    }    private int size;    private Node dummyHead;    public LinkedListDemo() {        size = 0;        dummyHead = new Node();    }    public int getSize() {        return this.size;    }    public boolean isEmpty() {        return size == 0;    }    public void add(int index, E e) {        if (index < 0 || index > size) {            throw new IllegalArgumentException("add error index.");        }        Node prev = dummyHead;        for (int i = 0; i < index; i++) {            prev = prev.next;        }        prev.next = new Node(e, prev.next);        size ++;    }    public void addFirst(E e) {        add(0, e);    }    public void addLast(E e) {        add(size, e);    }    public E remove(int index) {        if (index < 0 || index >= size) {            throw new IllegalArgumentException("remove error index.");        }        Node prev = dummyHead;        for (int i = 0; i < index; i++) {            prev = prev.next;        }        Node curNode = prev.next;        prev.next = curNode.next;        curNode.next = null;        return curNode.e;    }    public E removeFirst() {        return remove(0);    }    public E removeLast() {        return remove(size - 1);    }    public void removeElement(E e){        Node prev = dummyHead;        while (prev.next != null) {            if (prev.next.e.equals(e)) {                break;            }            prev = prev.next;        }        if (prev.next != null) {            Node delNode = prev.next;            prev.next = delNode.next;            delNode.next = null;            size --;        }    }    public void set(int index, E e) {        if (index < 0 || index > size) {            throw new IllegalArgumentException("set error index");        }        Node cur = dummyHead.next;        for (int i = 0; i < index; i++) {            cur = cur.next;        }        cur.e = e;    }    public E get(int index) {        if (index < 0 || index >= size) {            throw new IllegalArgumentException("Get error index");        }        Node cur = dummyHead.next;        for (int i = 0; i < index; i++) {            cur = cur.next;        }        return cur.e;    }    public E getFirst() {        return get(0);    }    public E getLast() {        return get(size - 1);    }                public boolean contains(E e) {        Node cur = dummyHead.next;        while (cur != null) {            if (cur.e.equals(e)) {                return true;            }            cur = cur.next;        }        return false;    }    @Override    public String toString() {        StringBuilder sb = new StringBuilder();        for (Node cur = dummyHead.next; cur != null; cur = cur.next) {            sb.append(cur.toString() + "--->");        }        sb.append("NULL");        return sb.toString();    }}