在JavaScript中实现堆栈和队列的最佳方法是什么?
我想做调车场算法我需要这些数据结构。
在JavaScript中实现堆栈和队列的最佳方法是什么?
我想做调车场算法我需要这些数据结构。
当前回答
问候,
在Javascript中,栈和队列的实现如下:
堆栈:堆栈是一个容器,其中的对象是根据后进先出(LIFO)原则插入和删除的。
方法将一个或多个元素添加到数组的末尾,并返回数组的新长度。 方法从数组中删除最后一个元素并返回该元素。
队列:队列是根据先进先出(FIFO)原则插入和删除对象的容器(线性集合)。
方法将一个或多个元素添加到数组的开头。 Shift:该方法从数组中移除第一个元素。
let stack = []; stack.push(1);//[1] stack.push(2);//[1,2] stack.push(3);//[1,2,3] console.log('It was inserted 1,2,3 in stack:', ...stack); stack.pop(); //[1,2] console.log('Item 3 was removed:', ...stack); stack.pop(); //[1] console.log('Item 2 was removed:', ...stack); let queue = []; queue.push(1);//[1] queue.push(2);//[1,2] queue.push(3);//[1,2,3] console.log('It was inserted 1,2,3 in queue:', ...queue); queue.shift();// [2,3] console.log('Item 1 was removed:', ...queue); queue.shift();// [3] console.log('Item 2 was removed:', ...queue);
其他回答
/*------------------------------------------------------------------
Defining Stack Operations using Closures in Javascript, privacy and
state of stack operations are maintained
@author:Arijt Basu
Log: Sun Dec 27, 2015, 3:25PM
-------------------------------------------------------------------
*/
var stackControl = true;
var stack = (function(array) {
array = [];
//--Define the max size of the stack
var MAX_SIZE = 5;
function isEmpty() {
if (array.length < 1) console.log("Stack is empty");
};
isEmpty();
return {
push: function(ele) {
if (array.length < MAX_SIZE) {
array.push(ele)
return array;
} else {
console.log("Stack Overflow")
}
},
pop: function() {
if (array.length > 1) {
array.pop();
return array;
} else {
console.log("Stack Underflow");
}
}
}
})()
// var list = 5;
// console.log(stack(list))
if (stackControl) {
console.log(stack.pop());
console.log(stack.push(3));
console.log(stack.push(2));
console.log(stack.pop());
console.log(stack.push(1));
console.log(stack.pop());
console.log(stack.push(38));
console.log(stack.push(22));
console.log(stack.pop());
console.log(stack.pop());
console.log(stack.push(6));
console.log(stack.pop());
}
//End of STACK Logic
/* Defining Queue operations*/
var queue = (function(array) {
array = [];
var reversearray;
//--Define the max size of the stack
var MAX_SIZE = 5;
function isEmpty() {
if (array.length < 1) console.log("Queue is empty");
};
isEmpty();
return {
insert: function(ele) {
if (array.length < MAX_SIZE) {
array.push(ele)
reversearray = array.reverse();
return reversearray;
} else {
console.log("Queue Overflow")
}
},
delete: function() {
if (array.length > 1) {
//reversearray = array.reverse();
array.pop();
return array;
} else {
console.log("Queue Underflow");
}
}
}
})()
console.log(queue.insert(5))
console.log(queue.insert(3))
console.log(queue.delete(3))
var stack = [];
stack.push(2); // stack is now [2]
stack.push(5); // stack is now [2, 5]
var i = stack.pop(); // stack is now [2]
alert(i); // displays 5
var queue = [];
queue.push(2); // queue is now [2]
queue.push(5); // queue is now [2, 5]
var i = queue.shift(); // queue is now [5]
alert(i); // displays 2
摘自“9个你可能不知道的JavaScript技巧”
没有数组(年代)
//Javascript stack linked list data structure (no array)
function node(value, noderef) {
this.value = value;
this.next = noderef;
}
function stack() {
this.push = function (value) {
this.next = this.first;
this.first = new node(value, this.next);
}
this.pop = function () {
var popvalue = this.first.value;
this.first = this.first.next;
return popvalue;
}
this.hasnext = function () {
return this.next != undefined;
}
this.isempty = function () {
return this.first == undefined;
}
}
//Javascript stack linked list data structure (no array)
function node(value, noderef) {
this.value = value;
this.next = undefined;
}
function queue() {
this.enqueue = function (value) {
this.oldlast = this.last;
this.last = new node(value);
if (this.isempty())
this.first = this.last;
else
this.oldlast.next = this.last;
}
this.dequeue = function () {
var queuvalue = this.first.value;
this.first = this.first.next;
return queuvalue;
}
this.hasnext = function () {
return this.first.next != undefined;
}
this.isempty = function () {
return this.first == undefined;
}
}
这是我的实现堆栈。
function Stack() {
this.dataStore = [];
this.top = 0;
this.push = push;
this.pop = pop;
this.peek = peek;
this.clear = clear;
this.length = length;
}
function push(element) {
this.dataStore[this.top++] = element;
}
function peek() {
return this.dataStore[this.top-1];
}
function pop() {
return this.dataStore[--this.top];
}
function clear() {
this.top = 0;
}
function length() {
return this.top;
}
var s = new Stack();
s.push("David");
s.push("Raymond");
s.push("Bryan");
console.log("length: " + s.length());
console.log(s.peek());
有很多方法可以在Javascript中实现堆栈和队列。上面的大多数答案都是非常肤浅的实现,我将尝试实现一些更可读(使用es6的新语法特性)和更健壮的东西。
下面是堆栈实现:
class Stack {
constructor(...items){
this._items = []
if(items.length>0)
items.forEach(item => this._items.push(item) )
}
push(...items){
//push item to the stack
items.forEach(item => this._items.push(item) )
return this._items;
}
pop(count=0){
//pull out the topmost item (last item) from stack
if(count===0)
return this._items.pop()
else
return this._items.splice( -count, count )
}
peek(){
// see what's the last item in stack
return this._items[this._items.length-1]
}
size(){
//no. of items in stack
return this._items.length
}
isEmpty(){
// return whether the stack is empty or not
return this._items.length==0
}
toArray(){
return this._items;
}
}
下面是如何使用堆栈:
let my_stack = new Stack(1,24,4);
// [1, 24, 4]
my_stack.push(23)
//[1, 24, 4, 23]
my_stack.push(1,2,342);
//[1, 24, 4, 23, 1, 2, 342]
my_stack.pop();
//[1, 24, 4, 23, 1, 2]
my_stack.pop(3)
//[1, 24, 4]
my_stack.isEmpty()
// false
my_stack.size();
//3
如果您想查看关于此实现的详细描述以及如何进一步改进,请阅读这里:http://jschap.com/data-structures-in-javascript-stack/
下面是es6中队列实现的代码:
class Queue{
constructor(...items){
//initialize the items in queue
this._items = []
// enqueuing the items passed to the constructor
this.enqueue(...items)
}
enqueue(...items){
//push items into the queue
items.forEach( item => this._items.push(item) )
return this._items;
}
dequeue(count=1){
//pull out the first item from the queue
this._items.splice(0,count);
return this._items;
}
peek(){
//peek at the first item from the queue
return this._items[0]
}
size(){
//get the length of queue
return this._items.length
}
isEmpty(){
//find whether the queue is empty or no
return this._items.length===0
}
}
下面是如何使用这个实现:
let my_queue = new Queue(1,24,4);
// [1, 24, 4]
my_queue.enqueue(23)
//[1, 24, 4, 23]
my_queue.enqueue(1,2,342);
//[1, 24, 4, 23, 1, 2, 342]
my_queue.dequeue();
//[24, 4, 23, 1, 2, 342]
my_queue.dequeue(3)
//[1, 2, 342]
my_queue.isEmpty()
// false
my_queue.size();
//3
要完整地了解如何实现这些数据结构以及如何进一步改进这些数据结构,您可能需要阅读jschap.com上的“在javascript中处理数据结构”系列。这是队列的链接——http://jschap.com/playing-data-structures-javascript-queues/