带虚拟头结点的单链表
public class DummyLinkedList<E>{
private int size;
private Node<E> first;
private static int ELEMENT_NOT_FOUND=-1;
private static class Node<E>{
Object element;
Node<E> next;
public Node(E element, Node<E> next) {
super();
this.element = element;
this.next = next;
}
}
public DummyLinkedList() {
first=new Node<E>(null, null);
}
public void clear() {
size=0;
first=null;
}
public int size() {
return size;
}
public int indexOf(E element){
if(element==null){
for(int i=0;i<size;i++){
if(node(i).element==null){
return i;
}
}
}else{
for(int i=0;i<size;i++){
if(node(i).element.equals(element)){
return i;
}
}
}
return ELEMENT_NOT_FOUND;
}
@Override
public String toString() {
StringBuilder sb=new StringBuilder();
Node<E> node=first.next;
sb.append("[");
for(int i=0;i<size;i++){
sb.append(node(i).element);
if(i!=size-1){
sb.append(",");
}
}
sb.append("]");
return sb.toString();
}
public boolean isEmpty() {
return size==0;
}
public boolean contains(Object element) {
for(int i=0;i<size;i++){
if(element==null){
if(node(i).element==null){
return true;
}
}else{
if(node(i).element.equals(element)){
return true;
}
}
}
return false;
}
public void add(Object element) {
add(size,element);
}
public Object get(int index) {
return node(index).element;
}
public Object set(int index, Object element) {
Node<E> temp=node(index);
E e=(E) temp.element;
temp.element=element;
return e;
}
public void add(int index, Object element) {
rangeCheckForAdd(index);
Node<E> prev=index==0?first:node(index-1);
Node<E> temp=new Node(element,prev.next);
prev.next=temp;
size++;
}
public E remove(int index) {
Node<E> temp=null;
Node<E> prev=index==0?first:node(index-1);
temp=prev.next;
prev.next=prev.next.next;
size--;
return (E) temp.element;
}
private Node node(int index){
rangeCheck(index);
Node temp=first.next;
for(int i=0;i<index;i++){
temp=temp.next;
}
return temp;
}
private void outBounds(int index){
throw new IndexOutOfBoundsException("Index:"+index+",Size: "+size);
}
private void rangeCheck(int index){
if(index<0||index>=size){
outBounds(index);
}
}
private void rangeCheckForAdd(int index){
if(index<0||index>size){
outBounds(index);
}
}
}
Processed:
0.013, SQL:
9
