js实现链表

js实现链表

 //js 链表
    class Node{
        constructor(element){
            this.value=element;
            this.next=null;
        }
    }
    class NodeList{
        constructor(){
            this.head=null;
            this.size=0
        }
        getNode(index){
            if(index<0||index>=this.size){
                throw new Eror('out range')
            }
            let p=this.head;
            for(let i=0;i<index;i++){
                p=p.next
            }
            return p
        }
        append(element){
            let node=new Node(element)
            if(this.size==0){
                this.head=node;
            }else{
                let current=this.getNode(this.size-1)
                current.next=node
            }
            this.size++
        }
        appendAt(element,position){
            if(position<0||position>this.size){
                throw new Error('out range ')
            }
            let node =new Node(element)
            if(position==0){
                node.next=this.head
                this.head=node
            }else{
                let current=this.getNode(position-1)
                node.next=current.next
                current.next=node
            }
            this.size++
        }
        removeAt(position){
            if(position<0||position>this.size-1){
                throw new Error('out range ')
            }
            let current=this.head
            if(position==0){
                this.head=current.next
            }else{
                let pre=this.getNode(position-1)
                current=pre.next
                pre.next=current.next
            }
            this.size--
        }
        //查找指定元素的索引
        indexOf(element){
            let current=this.head
            for(let i=0;i<this.size;i++){
                if(current.value==element){
                    console.log(i);
                    return i
                }
                current=current.next
            }
            return -1
        }
    }
   
    let h=new NodeList()
    h.append(1)
    h.append(2)
    h.append(3)
    h.appendAt(0,0)
    h.appendAt(4,4)
    h.indexOf(0)
    h.removeAt(4)
    console.dir(h)