package list;
public class Mylinkedlist {
private Node first; //第一个节点
private Node last; //最后一个节点
private int size = 0; // 节点的数量
public void addFrist(Object object){
Node node = new Node(object);
if (size == 0){
this.first = node;
this.last = node;
}else {
//把新增节点的下一个节点为第一个
node.next = this.first;
//吧新增节点作为第一个节点的上一个
this.first.prev = node;
//吧新增节点作为第一个节点
this.first = node;
}
size ++;
}
public void addLast(Object object){
//需要保存的节点对象
Node node = new Node(object);
if (size == 0){
this.first = node;
this.last = node;
}else {
//把新增节点作为之前最后一个节点的下一个节点
this.last.next = node;
//把之前最后一个节点作为新增节点的上一个节点
node.prev = this.last;
//把新增节点作为最后一个节点
this.last = node;
}
size ++;
}
//根据位置索引删除节点
public void removeindex(int index){
if (index>=size){
System.out.println("位置大于链表长度");
}
Node current = this.first;
if (index==0){
this.first = first.next;
}else {
int pos = 0;
while (pos != index){
current = current.next;
pos++;
}
current.prev.next= current.next;
current =current.prev;
}
size--;
}
//根据节点内容查找节点位置
public void findindex(Object object){
Node current = this.first;
if (current.next == null){
}
}
//根据节点内容删除节点
public void remove(Object object){
//找到被删除的节点
Node current = this.first;
for(int i =0;i<size;i++){
if (!current.ele.equals(object)){
if (current.next ==null){
return;
}
current = current.next;
}
}
//删除节点；
if (current ==first){
this.first = current.next;
this.first.prev =null;
}else if( current == last) {
this.last = current.prev;
this.last.next = null;
}else {
//把删除当前节点的下一个节点作为删除节点的上衣节点的next
current.prev.next = current.next;
//把删除节点的上一个节点作为删除节点的下一个节点的prev
current.next.prev = current.prev;
}
size--;
}
@Override
public String toString(){
if (size == 0){
return "[]";
}
StringBuilder stringBuilder = new StringBuilder(size*2+1);
Node current = this.first;
stringBuilder.append("[");
for (int i = 0;i<size;i++){
stringBuilder.append(current.ele);
if (i !=size-1){
stringBuilder.append(",");
}else {
stringBuilder.append("]");
}
current = current.next;
}
return stringBuilder.toString();
}
//链表中的每一个节点 使用内部类
class Node{
Node prev; //上一个节点
Node next; //下一个节点
Object ele; //当前节点中存储的数据
public Node(Object ele){
this.ele = ele;
}
}
}
+=============================
package list;
public class Mylinkedlisttest {
public static void main(String[] args) {
Mylinkedlist mylinkedlist = new Mylinkedlist();
mylinkedlist.addLast("B");
mylinkedlist.addLast("D");
mylinkedlist.addFrist("CC");
mylinkedlist.addFrist("AA");
System.out.println(mylinkedlist.toString());
//mylinkedlist.remove("D");
//System.out.println(mylinkedlist.toString());
mylinkedlist.removeindex(2);
System.out.println(mylinkedlist.toString());
}
}