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;
    }

}

如果有人需要它，你可以使用这个NPM包https://www.npmjs.com/package/data-structures-typescript，它有一个队列和堆栈，它支持javascript和typescript，它是通用的，所以你可以用你自己的值类型;)

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();

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());
    }
  }
}

下面是一个队列的链表版本，它也包括最后一个节点，这是@perkins建议的，也是最合适的。

// QUEUE Object Definition

var Queue = function() {
  this.first = null;
  this.last = null;
  this.size = 0;
};

var Node = function(data) {
  this.data = data;
  this.next = null;
};

Queue.prototype.enqueue = function(data) {
  var node = new Node(data);

  if (!this.first){ // for empty list first and last are the same
    this.first = node;
    this.last = node;
  } else { // otherwise we stick it on the end
    this.last.next=node;
    this.last=node;
  }

  this.size += 1;
  return node;
};

Queue.prototype.dequeue = function() {
  if (!this.first) //check for empty list
    return null;

  temp = this.first; // grab top of list
  if (this.first==this.last) {
    this.last=null;  // when we need to pop the last one
  }
  this.first = this.first.next; // move top of list down
  this.size -= 1;
  return temp;
};

我在实现BFS时遇到了这个线程。在疑惑为何表现如此糟糕之后，我做了一些调查。array.shift()通常在O(n)中运行，这将我的BFS运行时从O(V+E)增加到O(V^2+E)。

我没有从头开始实现一个队列，而是使用了npm包双端队列，它与之前使用的数组方法兼容，工作起来很有魅力。 deque可以用作堆栈或队列。

    //import package
    import Deque from 'double-ended-queue';

    //create queue
    let queue = new Deque();
    //append
    queue.push(item);
    //dequeue (get first item inserted)
    let firstItem = queue.shift();

    //pop (get last item inserted)
    let lastItem = queue.pop();