內容:棧、隊列、鏈表、集合、字典、散列表、樹node
//棧,方法包括入棧操做、出棧操做、返回棧頂元素、判斷棧是否爲空、清空棧、棧的長度 //這裏棧實例對象的方法均可看做閉包函數,items可看做類的私有變量,只有類實例的方法來訪問,而items也是棧內容的存儲實體。 function Stack(){ var items = []; this.push = function(ele){ items.push(ele); }; this.pop = function(){ items.pop(); }; this.size = function(){ return items.length; }; this.clear = function(){ items = []; }; this.peek = function(){ return items[items.length-1]; } this.isEmpty = function(){ return items.length > 0 ? false : true; } } var stack = new Stack(); console.log(stack); stack.push(2); console.log(stack.size()); console.log(stack.isEmpty());
//隊列,方法包括入隊操做、出隊操做、返回隊首元素、判斷隊列是否爲空、清空隊列、隊列的長度 function Queue(){ var items = []; this.inqueue = function(ele){ items.push(ele); }; this.outqueue = function(){ items.shift(); }; this.size = function(){ return items.length; }; this.clear = function(){ items = []; }; this.front = function(){ return items[0]; } this.isEmpty = function(){ return items.length > 0 ? false : true; } }
考慮到隊列中每一個元素具備優先級,因此隊列中的元素採用對象來實現,具備兩個屬性:元素的值和元素的優先級。編程
//優先級隊列 function PriorityQueue(){ var items = []; function QueueElement(element,priority){ this.element = element; this.priority = priority; } this.inqueue = function(element,priority){ var queueElement = new QueueElement(element,priority); if(this.isEmpty()){ items.push(queueElement); }else{ for(var i=0;i<items.length;i++){ if(items[i].priority > priority){ items.splice(i,0,queueElement); break; }else if(i === (items.length-1)){ items.push(queueElement); break; // 這裏必定要break,否則會循環插入,致使堆溢出 } } } }; this.outqueue = function(){ items.shift(); }; this.size = function(){ return items.length; }; this.clear = function(){ items = []; }; this.front = function(){ return items[0].element; } this.isEmpty = function(){ return items.length > 0 ? false : true; } this.get = function(){ return items; } }
能夠換個角度想:一排凳子,全部人循環去坐,擊鼓以後,坐在第一個凳子(隊頭)上的人淘汰,即下面代碼參考的思路。數組
//循環隊列 //擊鼓傳花遊戲,以固定循環次數來模擬每輪擊鼓的固定時長,該遊戲會一輪一輪迭代,每輪淘汰一人,直到只剩最後一人即爲勝者 function hotPotato(namelist,num){ var queue = new Queue(); for(var i=0;i<namelist.length;i++){ queue.inqueue(namelist[i]); } while(queue.size() > 1){ for(i=0;i<num;i++){ var nowElement = queue.front(); queue.outqueue(); queue.inqueue(nowElement); } var deletElement = queue.front(); queue.outqueue(); console.log(deletElement+"在擊鼓傳花遊戲中被淘汰"); } return queue.front(); } var list = ["hahah","askdjvzxv","uuuuu","aaaaa","bbbbbb","ccccc"]; var winner = hotPotato(list,5); console.log("勝利者是:"+winner);
//鏈表,元素在內存中非連續放置,方法包括鏈表尾部加入/刪除元素,鏈表指定位置加入/刪除元素,找出元素在鏈表中的索引,鏈表是否爲空,鏈表的長度 function LinkedList(){ var head = null;//鏈表第一個元素的引用 var length = 0;//鏈表的長度,否則尋求size很麻煩 var end = null;//鏈表最後一個元素的引用,方便插入/刪除元素 function Node(element){ this.element = element; this.next = null; } //從鏈表尾部加入node元素 this.appendList = function(element){ var node = new Node(element); if(head === null){ head = node; }else{ end.next = node; } end = node; length++; }; //從鏈表指定位置加入node元素,0表示在鏈表頭插入該元素 this.appendListAt = function(position,element){ var node = new Node(element); if(position > 0){ var frontNode = this.findNodeAt(position); var afterNode = frontNode.next; frontNode.next = node; node.next = afterNode; length++; }else if(position === 0){ node.next = head; head = node; length++; } }; //從鏈表尾部刪除node元素 this.removeList = function(){ if(head !== null){ var findNode = this.findNodeAt(length-1); end = findNode; findNode.next = null; length--; } }; //從鏈表指定位置刪除node元素 this.removeListAt = function(position){ if(position > 1){ //永遠檢測用戶輸入 var frontNode = this.findNodeAt(position-1); var afterNode = frontNode.next.next; frontNode.next = afterNode; length--; }else if(position = 1){ head = head.next; length--; } }; //鏈表的大小 this.size = function(){ return length; }; this.isEmpty = function(){ return head === null ? true : false; } this.toString = function(){ var iterNode = head; var outString = []; outString.push(head.element); for(var i=1;i<length;i++){ iterNode = iterNode.next; outString.push(iterNode.element); } return outString; } //封裝一個可共用的函數,找出指定位置的node元素 this.findNodeAt = function(position){ var iterNode = head; while(position > 1){ iterNode = iterNode.next; position--; } return iterNode; } }
//集合,集合類的方法包括添加/刪除元素,是否有某值,清除集合,集合大小 function Set(){ var items = {}; this.has = function(value){ return items.hasOwnProperty(value); } //向集合中添加元素 this.add = function(value){ if(!this.has(value)){ items[value] = value; return true; } return false; } //刪除集合中的元素 this.remove = function(value){ if(this.has(value)){ delete items[value]; // 刪除元素的屬性 } return false; } this.size = function(){ return Object.keys(items).length; } this.clear = function(){ items = {}; } this.values = function(){ return Object.keys(items); //返回對象自身中可枚舉屬性 } //集合的交集,並集,差集,子集方法 //並集 this.union = function(setB){ var setAvalues = this.values(); var setUnion = new Set(); for(var i=0;i<setAvalues.length;i++){ setUnion.add(setAvalues[i]); } var setBvalues = setB.values(); for(var j=0;j<setBvalues.length;j++){ setUnion.add(setBvalues[j]); } return setUnion; } //交集 this.intersection = function(setB){ var setAvalues = this.values(); var intersectionSet = new Set(); var setBvalues = setB.values(); for(var i=0;i<setAvalues.length;i++){ if(setB.has(setAvalues[i])){ intersectionSet.add(setAvalues[i]); } } return intersectionSet; } //差集 this.difference = function(setB){ var setAvalues = this.values(); var differenceSet = new Set(); var setBvalues = setB.values(); for(var i=0;i<setAvalues.length;i++){ if(!setB.has(setAvalues[i])){ differenceSet.add(setAvalues[i]); } } return differenceSet; } //子集 this.isSubsetOf = function(setB){ var setAvalues = this.values(); var setBvalues = setB.values(); for(var i=0;i<setAvalues.length;i++){ if(!setB.has(setAvalues[i])){ return false; } } return true; } }
//採用對象來實現字典,以key-value的形式存儲,由於對象中的屬性無序,字典的方法包括經過key來添加/刪除元素,是否有某值,清除字典,字典大小 function Dictionary(){ var items = {}; this.has = function(key){ return items.hasOwnProperty(key); } //向字典中添加元素 this.set = function(key,value){ if(!this.has(key)){ items[key] = value; return true; } return false; } //刪除字典中的元素 this.remove = function(key){ if(this.has(key)){ delete items[key]; return true; } return false; } //獲取固定的值 this.get = function(key){ return this.has(key) ? items[key] : undefined; } this.size = function(){ return Object.keys(items).length; } this.clear = function(){ items = {}; } this.keys = function(){ return Object.keys(items); //返回對象自身中可枚舉屬性 } this.values = function(){ var res = []; for(key in items){ if(items.hasOwnProperty(key)){ res.push(items[key]); } } return res; } //獲取整個字典對象 this.getItems = function(){ return items; } }
//二叉搜索樹 function BinarySearchTree(){ var rootNode = null; function TreeNode(key){ this.key = key; this.left = null; this.right = null; } //向樹中插入新節點 this.insert = function(key){ var treeNode = new TreeNode(key); if(rootNode === null){ rootNode = treeNode; }else{ insertNode(rootNode,treeNode); } } function insertNode(node,treeNode){ if(treeNode.key < node.key){ if(node.left === null){ node.left = treeNode; }else{ insertNode(node.left,treeNode); } }else if(treeNode.key > node.key){ if(node.right === null){ node.right = treeNode; }else{ insertNode(node.right,treeNode); } } } //先序遍歷 this.preOrderTraverse = function(){ if(rootNode === null){ console.log("沒有節點"); }else{ pretraverse(rootNode); } } function pretraverse(node){ if(node !== null){ pretraverse(node.left); console.log(node.key); pretraverse(node.right); } } //中序遍歷 this.inOrderTraverse = function(){ if(rootNode === null){ console.log("沒有節點"); }else{ intraverse(rootNode); } } function intraverse(node){ if(node !== null){ console.log(node.key); intraverse(node.left); intraverse(node.right); } } //後序遍歷 this.posOrderTraverse = function(){ if(rootNode === null){ console.log("沒有節點"); }else{ postraverse(rootNode); } } function postraverse(node){ if(node !== null){ postraverse(node.left); postraverse(node.right); console.log(node.key); } } //移除樹中的節點 this.remove = function(key){ rootNode = removeNode(rootNode,key); } function removeNode(node,key){ if(node === null){ return null; } if(key < node.key){ node.left = removeNode(node.left,key); return node; //與下面三個return node的功能都是保證removeNode的返回值爲刪除節點後樹的根節點 }else if(key > node.key){ node.right = removeNode(node.right,key); return node; }else{ if(node !== null){ //考慮到被刪除節點的三種狀況 if((node.left === null) && (node.right === null)){ node = null;//這裏只是爲了垃圾回收node,下面做用都相似 return node;//這裏纔是刪除的功能,這裏的返回是爲了讓node.left = removeNode(node.left,key);中node.left=null; }else if((node.left === null) && (node.right !== null)){ var temp = node.right; node = null; return temp; }else if((node.left !== null) && (node.right === null)){ var temp = node.left; node = null; return temp; }else if((node.left !== null) && (node.right !== null)){ var findNode = findMin(node.right); node.key = findNode.key; node.right = removeNode(node.right,findNode.key); return node; } } } } function findMin(node){ while(node.left !== null){ node = node.left; } return node; } //查找某個節點 this.search = function(key){ var node = rootNode; while((node !== null) && (node.key !== key)){ if(key < node.key){ node = node.left; }else if(key > node.key){ node = node.right; } } return (node !== null) ? true : false; } //獲取樹中最小值 this.min = function(){ var node = rootNode; while(node.left !== null){ node = node.left; } return node.key; } //獲取樹中最大值 this.max = function(){ var node = rootNode; while(node.right !== null){ node = node.right; } return node.key; } this.getRootNodeKey = function(){ return rootNode.key; } }