自定义实现LinkedList

来源：互联网发布：便宜好用的汽车知乎编辑：程序博客网时间：2024/05/20 21:19

package cn.xz.MyLinkedlist;
/**
* 自定义实现一个LinkedList
* @author 谢樟
*
*/
public class MyLinkedList {

private Node First; //头节点
private Node Last; //尾节点

int size;
MyLinkedList(){          //构造函数
  First=new Node(null,null,null);
  Last=new Node(null,First,null);
  size=0;
}
public int size(){
  return size;
}
public void add(Object x){
  add(size(),x);
   }
public void add(int index,Object value){
      addBefore(getNode(index),value);
}
public void addBefore(Node p,Object value){
  Node newNode=new Node(value,p.previous,p);
  newNode.previous.next=newNode;
  p.previous=newNode;
  size++;
}
public Node getNode(int index){
  Node p=null;
  if(index<0||index>size){
   System.out.println("下标越界");;
  }
  if(index<size/2){
   p=First.next;
   for(int i=0;i<index;i++){
    p=p.next;
   }
  }
  else{
   p=Last;
   for(int i=size;i>index;i--){
    p=p.previous;
   }
  }
  return p;
}
public Object get(int index){
  Node p=First.next;
  for(int i=0;i<index;i++){
   p=p.next;
  }
  return p.element;
}
public Object remove(int index){
  Node p=getNode(index);
  p.previous.next=p.next;
  p.next.previous=p.previous;
  return p.element;
}
public static void main(String[] args) {
  MyLinkedList linklist=new MyLinkedList();
  linklist.add("a");
        System.out.println(linklist.get(0));
}

}
class Node{
Object element;
Node previous;
Node next;
Node(Object value,Node pre,Node next){
  element=value;
  previous=pre;
  this.next=next;
}
}

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