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

下面是我使用链表实现的堆栈和队列:

// Linked List function Node(data) { this.data = data; this.next = null; } // Stack implemented using LinkedList function Stack() { this.top = null; } Stack.prototype.push = function(data) { var newNode = new Node(data); newNode.next = this.top; //Special attention this.top = newNode; } Stack.prototype.pop = function() { if (this.top !== null) { var topItem = this.top.data; this.top = this.top.next; return topItem; } return null; } Stack.prototype.print = function() { var curr = this.top; while (curr) { console.log(curr.data); curr = curr.next; } } // var stack = new Stack(); // stack.push(3); // stack.push(5); // stack.push(7); // stack.print(); // Queue implemented using LinkedList function Queue() { this.head = null; this.tail = null; } Queue.prototype.enqueue = function(data) { var newNode = new Node(data); if (this.head === null) { this.head = newNode; this.tail = newNode; } else { this.tail.next = newNode; this.tail = newNode; } } Queue.prototype.dequeue = function() { var newNode; if (this.head !== null) { newNode = this.head.data; this.head = this.head.next; } return newNode; } Queue.prototype.print = function() { var curr = this.head; while (curr) { console.log(curr.data); curr = curr.next; } } var queue = new Queue(); queue.enqueue(3); queue.enqueue(5); queue.enqueue(7); queue.print(); queue.dequeue(); queue.dequeue(); queue.print();

如果你正在寻找带有一些基本操作(基于链表)的堆栈和队列数据结构的ES6 OOP实现,那么它可能是这样的:

Queue.js

import LinkedList from '../linked-list/LinkedList';

export default class Queue {
  constructor() {
    this.linkedList = new LinkedList();
  }

  isEmpty() {
    return !this.linkedList.tail;
  }

  peek() {
    if (!this.linkedList.head) {
      return null;
    }

    return this.linkedList.head.value;
  }

  enqueue(value) {
    this.linkedList.append(value);
  }

  dequeue() {
    const removedHead = this.linkedList.deleteHead();
    return removedHead ? removedHead.value : null;
  }

  toString(callback) {
    return this.linkedList.toString(callback);
  }
}

Stack.js

import LinkedList from '../linked-list/LinkedList';

export default class Stack {
  constructor() {
    this.linkedList = new LinkedList();
  }

  /**
   * @return {boolean}
   */
  isEmpty() {
    return !this.linkedList.tail;
  }

  /**
   * @return {*}
   */
  peek() {
    if (!this.linkedList.tail) {
      return null;
    }

    return this.linkedList.tail.value;
  }

  /**
   * @param {*} value
   */
  push(value) {
    this.linkedList.append(value);
  }

  /**
   * @return {*}
   */
  pop() {
    const removedTail = this.linkedList.deleteTail();
    return removedTail ? removedTail.value : null;
  }

  /**
   * @return {*[]}
   */
  toArray() {
    return this.linkedList
      .toArray()
      .map(linkedListNode => linkedListNode.value)
      .reverse();
  }

  /**
   * @param {function} [callback]
   * @return {string}
   */
  toString(callback) {
    return this.linkedList.toString(callback);
  }
}

上面例子中用于堆栈和队列的LinkedList实现可以在GitHub上找到。

使用两个堆栈构造一个队列。

O(1)用于入队和出队操作。

class Queue {
  constructor() {
    this.s1 = []; // in
    this.s2 = []; // out
  }

  enqueue(val) {
    this.s1.push(val);
  }

  dequeue() {
    if (this.s2.length === 0) {
      this._move();
    }

    return this.s2.pop(); // return undefined if empty
  }

  _move() {
    while (this.s1.length) {
      this.s2.push(this.s1.pop());
    }
  }
}
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”

数组。

栈:

var stack = [];

//put value on top of stack
stack.push(1);

//remove value from top of stack
var value = stack.pop();

队列:

var queue = [];

//put value on end of queue
queue.push(1);

//Take first value from queue
var value = queue.shift();