Java-数据结构-LinkedList链表

LinkedList实现：

package cn.meowrain.Datastructure.collection;

public class LinkedList<E> {
    //链表的头结点，用于连接之后的所有结点
    private final Node<E> head = new Node<>(null);
    private int size;

    public void add(E element, int index) {
        if (index < 0 || index > size) {
            throw new IndexOutOfBoundsException("错误范围,位置不合法,合法范围为：0~" + size);
        }
        Node<E> prev = head;
        for (int i = 0; i < index; i++) {
            prev = prev.next;
        }
        Node<E> node = new Node<>(element);
        node.next = prev.next;
        prev.next = node;

        size++;
    }

    private static class Node<E> {
        private final E element;
        private Node<E> next;

        public Node(E e) {
            this.element = e;
        }

    }

    public int size() {
        return size;
    }
    public E remove(int index){
        if(index<0||index>size-1)
            throw new IndexOutOfBoundsException("删除位置非法，合法删除位置范围为： 0~"+ (size-1));
        Node<E> prev = head;
        for(int i = 0;i<index;i++){
            prev = prev.next;
        }
        E element = prev.next.element;
        prev.next = prev.next.next;
        return element;
    }

    public E get(int index){
        if(index<0||index>size-1)
            throw new IndexOutOfBoundsException("获取位置非法，合法获取位置范围为： 0~"+ (size-1));
        Node<E> prev = head;
        for(int i = 0;i<=index;i++){
            prev = prev.next;
        }
        E element = prev.element;
        return element;
    }
    @Override
    public String toString() {
        StringBuilder builder = new StringBuilder();
        Node<E> node = head.next;
        while (node != null) {
            builder.append(node.element).append(" ");
            node = node.next;
        }
        return builder.toString();
    }
}

```
## LinkedListRunner.java
```java
package cn.meowrain.Datastructure;

import cn.meowrain.Datastructure.collection.LinkedList;

public class LinkedListRunner {
    public static void main(String[] args) {
        LinkedList<String> list = new LinkedList<>();
        list.add("bbb",0);
        list.add("ccc",1);
        list.add("ddd",2);
        System.out.println(list);
        System.out.println(list.size());
        String a = list.remove(1);
        System.out.println(a);
        System.out.println(list);
        list.add("ccc",1);
        System.out.println(list.get(1));
    }
}

```