js在Node.js下實現單連結串列與雙連結串列結構

單連結串列（LinkedList）的javascript實現:

npmjs相關庫：

complex-list、smart-list、singly-linked-list

程式設計思路：

（1）.add方法用於將元素追加到連結串列尾部，藉由insert方法來實現。

（2）.注意各個函式的邊界條件處理。

自己的實現:SingleNode.js

[JavaScript] 純文字檢視 複製程式碼
(function(){
 "use strict";
  
 function Node(element){
  this.element = element;
  this.next = null;
 }
  
 module.exports = Node;
})();

LinkedList.js

[JavaScript] 純文字檢視 複製程式碼
(function(){
 "use strict";
  
 var Node = require("./lib/SingleNode");
  
 function LinkedList(){
  this._head = new Node("This is Head Node.");
  this._size = 0;
 }
  
 LinkedList.prototype.isEmpty = function(){
  return this._size === 0;
 };
  
 LinkedList.prototype.size = function(){
  return this._size;
 };
  
 LinkedList.prototype.getHead = function(){
  return this._head;
 };
  
 LinkedList.prototype.display = function(){
  var currNode = this.getHead().next;
  while(currNode){
   console.log(currNode.element);
   currNode = currNode.next;
  }
 };
  
 LinkedList.prototype.remove = function(item){
  if(item) {
   var preNode = this.findPre(item);
   if(preNode == null)
    return ;
   if (preNode.next !== null) {
    preNode.next = preNode.next.next;
    this._size--;
   }
  }
 };
  
 LinkedList.prototype.add = function(item){
  this.insert(item);
 };
  
 LinkedList.prototype.insert = function(newElement, item){
  var newNode = new Node(newElement);
  var finder = item ? this.find(item) : null;
  if(!finder){
   var last = this.findLast();
   last.next = newNode;
  }
  else{
   newNode.next = finder.next;
   finder.next = newNode;
  }
  this._size++;
 };
  
 /*********************** Utility Functions ********************************/
  
 LinkedList.prototype.findLast = function(){
  var currNode = this.getHead();
  while(currNode.next){
   currNode = currNode.next;
  }
  return currNode;
 };
  
 LinkedList.prototype.findPre = function(item){
  var currNode = this.getHead();
  while(currNode.next !== null && currNode.next.element !== item){
   currNode = currNode.next;
  }
  return currNode;
 };
  
 LinkedList.prototype.find = function(item){
  if(item == null)
   return null;
  var currNode = this.getHead();
  while(currNode && currNode.element !== item){
   currNode = currNode.next;
  }
  return currNode;
 };
  
 module.exports = LinkedList;
})();

雙連結串列（DoubleLinkedList）的javascript實現:

npmjs相關庫：

complex-list、smart-list

程式設計思路：

（1）.雙連結串列多了一個指向前趨的指標，故單連結串列中的輔助函式findPre就不需要了。

（2）.增加了反向輸出方法。

（3）.注意邊界條件的處理。

自己的實現

DoubleNode.js

[JavaScript] 純文字檢視 複製程式碼
(function(){
 "use strict";
  
 function Node(element){
  this.element = element;
  this.next = null;
  this.previous = null;
 }
  
 module.exports = Node;
})();

DoubleLinkedList.js

[JavaScript] 純文字檢視 複製程式碼
(function(){
 "use strict";
 var Node = require("./lib/DoubleNode");
  
 function DoubleLinkedList(){
  this._head = new Node("This is Head Node.");
  this._size = 0;
 }
  
 DoubleLinkedList.prototype.getHead = function(){
  return this._head;
 };
  
 DoubleLinkedList.prototype.isEmpty = function(){
  return this._size === 0;
 };
  
 DoubleLinkedList.prototype.size = function(){
  return this._size;
 };
  
 DoubleLinkedList.prototype.findLast = function(){
  var currNode = this.getHead();
  while(currNode.next){
   currNode = currNode.next;
  }
  return currNode;
 };
  
 DoubleLinkedList.prototype.add = function(item){
  if(item == null)
   return null;
  this.insert(item);
 };
  
 DoubleLinkedList.prototype.remove = function(item){
  if(item) {
   var node = this.find(item);
   if(node == null)
    return ;
   if (node.next === null) {
    node.previous.next = null;
    node.previous = null;
   } else{
    node.previous.next = node.next;
    node.next.previous = node.previous;
    node.next = null;
    node.previous = null;
   }
   this._size--;
  }
 };
  
 DoubleLinkedList.prototype.find = function(item){
  if(item == null)
   return null;
  var currNode = this.getHead();
  while(currNode && currNode.element !== item){
   currNode = currNode.next;
  }
  return currNode;
 };
  
 DoubleLinkedList.prototype.insert = function(newElement, item){
  var newNode = new Node(newElement);
  var finder = item ? this.find(item) : null;
  if(!finder){
   var last = this.findLast();
   newNode.previous = last;
   last.next = newNode;
  }
  else{
   newNode.next = finder.next;
   newNode.previous = finder;
   finder.next.previous = newNode;
   finder.next = newNode;
  }
  this._size++;
 };
  
 DoubleLinkedList.prototype.dispReverse = function(){
  var currNode = this.findLast();
  while(currNode != this.getHead()){
   console.log(currNode.element);
   currNode = currNode.previous;
  }
 };
  
 DoubleLinkedList.prototype.display = function(){
  var currNode = this.getHead().next;
  while(currNode){
   console.log(currNode.element);
   currNode = currNode.next;
  }
 };
  
 module.exports = DoubleLinkedList;
})();