java1.8 LinkedList的結構原理

public class Test {
//鏈表，先進先出。雙向鏈表結構，項目中可也會用到，其他方法自行研究。也可引申出紅黑樹，敬請關注我的博客
    public static void main(String[] args) {
        MyLinkedList linkedList = new MyLinkedList();
        linkedList.add("a1");
        linkedList.add("a2");
//        System.out.println(linkedList.get(1)); //獲取索引爲1的值 打印a2
        System.out.println(linkedList.toString());//打印 [a1,a2]
    }
}
class MyLinkedList<E>{
     Node<E> last;//只記錄最後一個節點
     Node<E> first;//只記錄第一個節點
     int size = 0;//記錄節點的個數

    void add(E e){
        Node<E> prev = last;//當前節點的上個節點，也可理解爲當前集合的最後一個節點
        Node<E> node = new Node<>(prev,e,null);//當前節點
        last = node;//當前節點作爲最後一個節點賦給成員變量
        if (prev==null){//如果當前節點的上個節點爲空，則說明當前節點爲第一個數
            first = node;
        }else {//否則上個節點的下個節點指向當前節點
            prev.next = node;
        }
        size++;
    }
    public int size(){
        return size;
    }

    @Override
    public String toString() {
        Node<E> node = first;
        String content = "";
        for (int i = 0; i < size; i++) {
            if (i==0){
                content =  node.elment +"";
            }else {
                content = content + "," + node.elment;
            }
            node = node.next;
        }

        return "["+content+"]";
    }

    public E get(int index){
        Node<E> node = first;
        for (int i = 0; i < index; i++) {//
            node = node.next;
        }
        return node.elment;
    }
}

class Node<E> {
    Node<E> prev;
    E elment;
    Node<E> next;
    public Node(Node<E> prev, E e, Node<E> next){
        this.prev = prev;
        this.elment = e;
        this.next = next;
    }
}