https://github.com/cesarvr/deque-js

JS Port of Python Deques. Deques are a generalization of stacks and queues (the name is pronounced “deck” and is short for “double-ended queue”).
https://github.com/cesarvr/deque-js

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JS Port of Python Deques. Deques are a generalization of stacks and queues (the name is pronounced “deck” and is short for “double-ended queue”).

• Host: GitHub
• URL: https://github.com/cesarvr/deque-js
• Owner: cesarvr
• Created: 2020-03-27T14:04:35.000Z (over 4 years ago)
• Default Branch: master
• Last Pushed: 2022-02-11T01:33:06.000Z (almost 3 years ago)
• Last Synced: 2023-05-15T07:20:20.370Z (over 1 year ago)
• Language: JavaScript
• Size: 5.86 KB
• Stars: 0
• Watchers: 0
• Forks: 0
• Open Issues: 1
• Metadata Files:
  • Readme: README.md

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README

        
# Deque

this is just a implementation of Python [deques](https://docs.python.org/2/library/collections.html#collections.deque) in JS. Deques are a generalization of stacks and queues (the name is pronounced “deck” and is short for “double-ended queue”).

Though list objects support similar operations, they are optimized for fast fixed-length operations and incur O(n) memory movement costs for pop(0) and insert(0, v) operations which change both the size and position of the underlying data representation.

## Install 

```sh

npm install dqs 

```

## Usage

```js

let dqueue = require('dqs')

```

## Methods 

#### insert(x)

Add x to the right side of the deque.

#### all 

Return all the objects in an Array.

#### clear() 

Remove all elements from the deque leaving it with length 0.

#### count(x)

Count the number of deque elements equal to x.

#### pop()

Remove and return an element from the right side of the deque. If no elements are present, raises an IndexError.

#### popleft()

Remove and return an element from the left side of the deque. If no elements are present, raises an IndexError.

```js

let dq = new DQueue([2,3,0,1])

let v1 = dq.popLeft()

let v2 = dq.popLeft()

console.log(v1, v2) // 2 3

console.log(dq.all()) // [0,1]

```

#### rotate(n=1)

Rotate the deque n steps to the right. If n is negative, rotate to the left.

```js

let dqueue = new DQS([2,3,0,1])

dqueue.rotate(-2)

//[0,1,2,3]

```

When the deque is not empty, rotating one step to the right is equivalent to d.appendleft(d.pop()), and rotating one step to the left is equivalent to d.append(d.popleft()).