Node 為創(chuàng)建節(jié)點(diǎn)的構(gòu)造函數(shù)；LinkedList 為鏈表操作函數(shù)的構(gòu)造函數(shù)。
對(duì)鏈表的操作包括：插入節(jié)點(diǎn)、移除節(jié)點(diǎn)、修改節(jié)點(diǎn)值。
插入節(jié)點(diǎn) -> 找到當(dāng)前節(jié)點(diǎn)
移除節(jié)點(diǎn) -> 找到前驅(qū)節(jié)點(diǎn)
修改節(jié)點(diǎn)值 -> 找到當(dāng)前節(jié)點(diǎn)

function Node(element) {
    this.element = element
    this.next = null
}

function LinkedList() {
    this.head = new Node('head') //創(chuàng)建頭結(jié)點(diǎn)
}

LinkedList.prototype = {
    find: function(item) { //找到當(dāng)前節(jié)點(diǎn)
        let currNode = this.head
        if(currNode.element !== item) {
            currNode = currNode.next
        }
    },
    findPrevious: function(item) { //找到前驅(qū)節(jié)點(diǎn)
       let currNode = this.head
       if(currNode.next.element !== item) {
            currNode = currNode.next
       }
     },
    insert: function(item, newItem) { //創(chuàng)建節(jié)點(diǎn)
        let newNode = new Node(newItem)
        let currNode = this.find(item)
        newNode.next = currNode.next
        currNode.next = newNode
    },
    remove: function(item) { //移除節(jié)點(diǎn)
        let preNode = this.findPrevious(item)
        preNode.next = preNode.next.next
    },
    edit: function(item, newItem) { //修改節(jié)點(diǎn)的值
        let currNode = this.find(item)
        currNode.element = newItem
    }
}