/*JS实现一个基于对象的链表*/

function Node(element){
    this.element = element;//节点存储的元素
    this.next = null;//节点指向的下一个节点，这里先设置为空
}

function LList(){
    this.head = new Node("head");//生成一个头节点
    this.find = find;//在链表中找到某个节点
    this.insert = insert;//在链表中某个元素后面插入某个节点元素
    this.display = display;//在将链表中的节点元素显示出来
    this.findPrevious = findPrevious;//找到某个节点的上一个节点
    this.remove = remove;//删除某个节点
}

function remove(item) {
    var prevNode = this.findPrevious(item);
    if (!(prevNode.next == null)) {
        prevNode.next = prevNode.next.next;
    }
}

function findPrevious(item) {
    var currNode = this.head;
    while (!(currNode.next == null) &&
        (currNode.next.element != item)) {
        currNode = currNode.next;
    }
    return currNode;
}

function display() {
    var currNode = this.head;
    var nodestr = "";
    while (!(currNode.next == null)) {
        nodestr +="  "+currNode.next.element;
        currNode = currNode.next;
    }
    console.log(nodestr);
}

function find(item) {
    var currNode = this.head;
    while (currNode.element != item) {
        currNode = currNode.next;
    }
    return currNode;

}

function insert(newElement, item) {
    var newNode = new Node(newElement);
    var current = this.find(item);
    newNode.next = current.next;
    current.next = newNode;
}



/*测试例子*/
var num = new LList();
num.insert("a1","head");
num.insert("b1","a1");
num.insert("c1","b1");
num.display();//  a1  b1  c1
num.remove("b1");
num.display();//  a1  c1