114 lines
3.0 KiB
JavaScript
114 lines
3.0 KiB
JavaScript
/**
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* 1）单链表的插入、删除、查找操作；
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* 2）链表中存储的是int类型的数据；
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*/
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class Node {
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constructor (element) {
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this.element = element
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this.next = null
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}
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}
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class LinkedList {
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constructor () {
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this.head = new Node('head')
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}
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// 根据value查找节点
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findByValue (item) {
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let currentNode = this.head.next
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while (currentNode !== null && currentNode.element !== item) {
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currentNode = currentNode.next
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}
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console.log(currentNode)
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return currentNode === null ? -1 : currentNode
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}
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// 根据index查找节点，下标从0开始
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findByIndex (index) {
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let currentNode = this.head.next
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let pos = 0
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while (currentNode !== null && pos !== index) {
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currentNode = currentNode.next
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pos++
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}
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console.log(currentNode)
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return currentNode === null ? -1 : currentNode
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}
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// 向链表末尾追加节点
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append(newElement) {
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const newNode = new Node(newElement)
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let currentNode = this.head
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while(currentNode.next) {
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currentNode = currentNode.next
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}
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currentNode.next = newNode
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}
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// 指定元素向后插入
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insert (newElement, element) {
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const currentNode = this.findByValue(element)
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if (currentNode === -1) {
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console.log('未找到插入位置')
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return
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}
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const newNode = new Node(newElement)
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newNode.next = currentNode.next
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currentNode.next = newNode
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}
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// 查找前一个
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findPrev (item) {
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let currentNode = this.head
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while (currentNode.next !== null && currentNode.next.element !== item) {
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currentNode = currentNode.next
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}
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if (currentNode.next === null) {
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return -1
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}
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return currentNode
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}
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// 根据值删除
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remove (item) {
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const prevNode = this.findPrev(item)
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if (prevNode === -1) {
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console.log('未找到元素')
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return
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}
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prevNode.next = prevNode.next.next
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}
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// 遍历显示所有节点
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display () {
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let currentNode = this.head.next // 忽略头指针的值
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while (currentNode !== null) {
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console.log(currentNode.element)
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currentNode = currentNode.next
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}
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}
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}
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// Test
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const LList = new LinkedList()
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LList.append('chen')
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LList.append('curry')
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LList.append('sang')
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LList.append('zhao') // chen -> curry -> sang -> zhao
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console.log('-------------insert item------------')
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LList.insert('qian', 'chen') // 首元素后插入
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LList.insert('zhou', 'zhao') // 尾元素后插入
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LList.display() // chen -> qian -> curry -> sang -> zhao -> zhou
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console.log('-------------remove item------------')
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LList.remove('curry')
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LList.display() // chen -> qian -> sang -> zhao -> zhou
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console.log('-------------find by item------------')
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LList.findByValue('chen')
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console.log('-------------find by index------------')
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LList.findByIndex(2)
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console.log('-------------与头结点同值元素测试------------')
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LList.insert('head', 'sang')
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LList.display() // chen -> qian -> sang -> head -> zhao -> zhou
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LList.findPrev('head') // sang
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LList.remove('head')
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LList.display() // chen -> qian -> sang -> zhao -> zhou
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